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PSORIASIS
1. INTRODUCTION
Psoriasis is a chronic inflammatory disease of unknown cause. In 1992, Psoriasis is the fifth commonest skin condition found in all new cases attending Social Hygiene Service and it is one of the common skin diseases worldwide.
Another factor for psoriasis commonly seen by doctors is that this disease up till now there is no cure for psoriasis. It is highly likely that patient will shop from one doctor to another, from one clinic to another and usually the most severe cases will be ended up in our management. Frustration may not only be found in the patient but sometimes from the doctor and health provider as well for this recalcitrant and persistent condition. However, equipped with patience, the modern treatment often offers a large measure of hope to sufferers.
2. CLINICAL FEATURE
Psoriasis is a chronic erythemato-squamous condition characterized by sharply circumscribed salmon pink patches, plaques covered with silvery scales , . The onset of the disease is usually gradual and becomes noticeable by the patient from 30 years onwards. However, in patient with family history positive for psoriasis, there may be earlier onset at teenager or even below ten. In these cases, the prognosis is worse. From the study in China², the majority (97.98%) of the types of psoriasis is the psoriasis vulgaris or chronic plaque type. We have similar experience in Social Hygiene Clinic (see Table I).
Table I
Conditions Incidence %
Chronic plaque 506 95.8
Guttate 14 2.7
Flexural 0 0
Erythrodermic 0 0
Generalized pustular 4 0.75
Localized pustular 4 0.75
All Psoriasis 528 3.97
All new skin cases 13310 100.00
The classification of psoriasis may vary with different author's preference but for simplicity and practicability, I take the following classification for psoriasis : I. Non-pustular psoriasis II. Pustular psoriasis III. Psoriasis with arthropathy. They can be subclassified further into :
2.1 Non-pustular Psoriasis
(i) Chronic Plaque type
(ii) Acute Guttate
(iii) Inverse, flexural
(iv) Erythrodermic
(v) Regional : scalp, palms & soles, nails
(vi) Unstable nummular
(vii) Sebo-psoriasis
2.2 Pustular Psoriasis
(i) Generalized Pustular psoriasis (von Zumbusch)
(ii) Generalized pustular psoriasis of palms & soles
2.3 Psoriasis with Arthropathy
5 Types of arthropathy found : oligoarticular asymmetrical arthritis, symmetrical involving small joints of fingers like rheumatoid arthritis, classical distal arthropathy involving distal interphalangeal joints, destructive arthritis mutilans and psoriatic spondyloarthropathy which is similar to ankylosing spondylitis.
Two interesting phenomena occur in Psoriasis. They are mutually exclusive : Koebner and reverse Koebner responses. Any form of trauma may result in psoriasis appearing in the traumatized areas which is known as Koebner phenomenon or isomorphic response. A degree of healing may occur when a psoriatic plaque is traumatized which is the reverse Koebner phenomenon. It also explains why some patient found cryotherapy is useful to suppress psoriasis.
The commonest form of psoriasis is the chronic plaque type which usually presents as brightly erythematous scaly plaques at the predisposed areas i.e. the extensor aspect, the tip of elbows, knees, sacral area, the scalp. They may be associated with no symptoms to moderate pruritus. Excessive dandruff and scaling from the lesional area may be an early complaint. Family history is not very commonly found in this group because the other family members may not having the disease at all or if possess, usually in a very mild degree. Patient may have history of acute guttate psoriasis before but it either never clears or reappears as plaque form. The most useful form to confirm the diagnosis is to use the wooden spatula to scrape the surface of the suspected lesion, profuse silvery scaling can easily be generated. The well demarcated border of the plaque, the prominent scaling, other associated findings such as symmetrical distribution with scalp involvement, Auspitz sign (to forcibly remove the superficial scaling on top of the psoriatic plaque will reveal the fine dots of bleeding points) and the characteristic colour which is also quite obvious in Chinese patients will lead to the diagnosis of the disease without difficulties. The course of the disease is very chronic. I seldom see a case of persistent, sustained long term remission because either remission may not be common (it had been quoted from 20 to 50% when following the psoriatic patient long enough e.g. 50 years), or remitted patient will not turn up in the clinic to thank you, or patients seen by different doctors every time attending Social Hygiene Clinic. It usually waxes and wanes, tend to improve in summer and worsen in winter. However, with correct therapy, majority can lead normal life and there is definitely a chance of spontaneous remission though the younger the onset of the disease, the more likely it will persist till elderly. The presence of a strong positive family history will be another poor prognostic factor.
However, other forms of psoriasis though much rarer, they do present diagnostic problem occasionally. The erythrodermic psoriasis may be mistaken as other causes for erythroderma such as seborrhoeic eczema, drug eruption, pityriasis rubra pilaris. Flexural psoriasis may lack the prominent silvery scaling because the flexural areas affected usually appear as brightly erythematous, homogenous, well defined and sharply demarcated plaque or patch with or without super-infection with Candida.
Acute guttate psoriasis is often preceded by a history of sore throat 10 days to 2 weeks ago. It may be a streptococcal infection. The small guttate maculopapular scaly lesion still have the characteristic feature of psoriasis and hence there will be no diagnostic problem. Occasionally, pityriasis rosea, pityriasis lichenoides have to be excluded. The course of the disease initially will go into remission in few months time but it can reappear after another attack of infection and many do gradually become a chronic plaque type psoriatic case.
Regional psoriasis involving scalp, palm and soles are relatively common. They are often misdiagnosed as seborrhoeic dermatitis, keratoderma or chronic eczema of hand and feet before the more definite sign of psoriasis appear. Fortunately, the types of treatment do not differ much. Unstable nummular eczema can occasionally be seen and they have tendency to change from time to time, to either erythrodermic psoriasis or pustular psoriasis. There is low erythema threshold in this group of patients. Usually they are found in patients with psoriatic arthropathy. Topical irritants or sudden withdrawal of topical steroid may prone this group of patients flaring up of their diseases and they may be required hospitalized for stabilization.
Localized pustular psoriasis of palms and soles usually present as symmetrical, monomorphic eruption of small sterile pustular eruption on hands and feet. They are painful rather than pruritic. Very often, brownish thick wall pustules are found. They are resistant to treatment and will be quite disabling. Another form of local pustular psoriasis is asymmetrical involvement affecting distal phalanx with nail destruction. It is called acrodermatitis continua. It may change to generalized pustular form.
Generalized pustular psoriasis can present in a psoriatic prone patient who is given systemic steroid for other conditions and upon sudden withdrawal of the steroid, generalized pustular psoriasis will be precipitated for the first time. Occasionally, it develops from the unstable nummular psoriasis or acrodermatitis continua after inappropriate irritant therapy or withdrawal of extensive topical steroid. Pregnancy can sometimes associate with generalized pustular psoriasis. There are low grade fever, pain and burning sensation over the pustules. Systemic and constitutional upset may be severe. This requires in-patient management with bed-rest and institution of transient systemic therapy.
Many doctors may not consider the existence of this condition : sebo-psoriasis or seborrhoeic psoriasis. Very often, we can encounter conditions in which both psoriatic and seborrhoeic eczema features are present. I consider this a separate entity because it is not rare. In a genetically constituted psoriatics who can develop seborrhoeic eczema lesions at the scalp, eyebrows and regions of ears with characteristic morphology of psoriasis at these sites.
Nail involvement is commonly seen in all types of psoriasis which can affect the nail matrix and nail bed leading to pitting, discoloration, subungual hyperkeratosis, onycholysis, splinter haemorrhage. Circular area of discoloration of nail bed resembling an oil drop underneath the nail - oil drop sign is most characteristic for psoriatic nail.
Patients with AIDS develop severe recalcitrant form of psoriasis and psoriasis related disease such as Reiter's disease. The use of etretinate and anti-viral therapy such as zidovudine are necessary to control this type of psoriasis.
The clinical features of psoriasis especially chronic plaque type is so obvious and unique that seldom requires further investigations. However, differential diagnosis should be remember especially for other types of psoriasis. Eczema, psoriasiform drug eruption, lichen planus, discoid lupus erythematosus, lichen simplex chronica, pityriasis rubra pilaris, secondary syphilis, Bowen's disease, Paget's disease and superficial fungal infection will mimic chronic plaque type psoriasis. Pityriasis lichenoides chronica, pityriasis rosea can resemble guttate psoriasis. Candidal intertrigo, Hailey Hailey disease may be mistaken as flexural psoriasis. The keratoderma blenorrhagica (palmoplantar lesions) of Reiter's disease will be indistinguishable from localized pustular psoriasis.
3. INVESTIGATION
Skin biopsy is the most useful investigation e.g. in erythrodermic psoriasis. The typical histopathology of psoriasis (non-pustular form) is characterized by : 1) regular elongation of the rete ridges with thickening in their lower portion. 2) elongation and edema of the papillae. 3) thinning of the suprapapillary portions of the stratum malpighii with the occasional presence of a very small spongiform pustule. 4) the absence of granular layer 5) parakeratosis 6) presence of Munro microabscesses.
Radiological examination of the affected joints may confirm the psoriatic arthropathy. The following findings are characteristic signs of psoriatic arthropathy : 1) destructive distal interphalangeal arthropathy with bony ankylosis of the interphalangeal joints 2) abnormally wide joint spaces and well demarcated adjacent bony surfaces 3) bony proliferation of distal phalanx in great toe 4) resorption of tufts of distal phalanges of hands & feet.
4. MANAGEMENT IN SOCIAL HYGIENE SERVICE
4.1 General
Management of psoriasis requires a complete thorough history not only for the disease activities but also to include information about how the patient perceive and handle this condition in the past, the past treatment and the failed treatment and possible the cause of failure of the treatment. The sex, occupation and social background are all important factors to consider in the management and it will be very true that every patient will present an entirely different problem. The degree of acceptance of the condition by the patient and the knowledge on the condition will also affect the management plan.
Dietary manipulation has no place in management of psoriasis. Stress is one of the factor contributory to flare up of the condition though not agreed by all and stress can also be one of result of deteriorating psoriasis. Chinese herbs are not recommended because no single good control study have proven these to be effective alone without using the traditional western anti-psoriatic medication simultaneously. Many harmless placebo have been tried on this condition and it will not be surprising to read one or two reports claiming good effect on psoriasis, the progression of which can be affected by so many factors.
Alcohol intake should be discouraged because there is a positive correlation between psoriasis and alcohol intake and alcohol induced liver problems may preclude patient from receiving effective systemic therapy in future. Medications such as lithium, salicylates, iodine, beta blockers, naprosyn and penicillin have been implicated in exacerbating psoriasis. 80% of patients with psoriasis find that sunlight improves their conditions but the rest may find no change or even exacerbation. However, sunburn is always a precipitating factor because the scalded area will heal with new crops of psoriasis (the Koebner's phenomenon). Streptococcal infection if persistent or carried in the deep tonsil crypts should be eradicated with a course of antibiotics.
Some of the know aggravating factors if correctable should be removed or avoided. Climatotherapy can only be afforded by the rich and retired patients.
4.2 Topical
4.2.1 Emollient : It is indeed very useful to decrease fissure, cracking and scaling. Aqueous cream, Ung Emulsificant and 10% urea cream are commonly used in Psoriasis.
4.2.2 Tar : Pinetar, Coal tar are all useful. They can be in the lotion, shampoo, cream, paste, ointment forms. The commonly used items in Social Hygiene Service are : 3% tar paste, Ung 2-4-2 or Ung 1-2-1, 1% crude coal tar. They are good for the stable chronic plaque type. However, slow action, messy and sticky, poor smell, staining properties are all factors for it low acceptance in patients. Education and persuasion to patients are necessary to insist using the cream for few months' time before giving it up. It is an adjunctive component in the Goeckerman's regimen.
4.2.3 Sulphur and salicylate : 2% sulphur salicylate emulsion is a very common prescribed item to thick scalp psoriasis for its keratolytic effect.
4.2.4 Topical steroid : It is widely used not only by dermatologists but by the primary care doctors. Moderate potent steroids have to be used to suppress the psoriasis. Good examples are Synalar, Betnovate, Dermovate creams or ointments. However, only careful dermatologists will know when to stop them to avoid tachyphylaxis and rebound of the condition and what to control during the period of withdrawal.
4.2.5 Topical calcipotriol (Daivonex) cream : It has similar efficacy as that of potent steroid but lacks the local adverse effect of skin atrophy, rebound phenomena and tachyphylaxis. However, washing hands after application to avoid irritation and avoiding flexural and face area are one its limit. The expensive cost is also one of the limiting factor.
4.2.6 Dithranol : 0.25 % dithranol in Lassar paste can be tolerated by some patients with plaque type psoriasis at the shins, elbows and knees and with good therapeutic result. However, careful instruction of how to use and olive or mineral oil to remove the paste have to be prescribed as well. In-patient will be a good chance of giving a trial of this preparation. Adjunctive phototherapy as in Ingram regimen will be very helpful but only is possible in in-patient or day care centre. The commercial preparation of 1 to 4 % Dithranol ointment is good for the SCAT (Short contact Anthranol therapy). It is because the staining and stinging sensation that most patient dislike this regimen.
4.3 Systemic Therapy
The indications of systemic therapy will vary from one patient to the other because the degree of severity will be perceived differently by different patients with some correlation to the need or occupation of the patient. The choice of treatment depends on a number of factors such as :
(i) severity, extent, site of disease
(ii) compliance, intelligence of patient
(iii) sex (chance of conception), age of patient
(iv) presence of other systemic illness or skin conditions
(v) financial and time factors, motivations
(vi) limiting factors from available treatment facilities
(vii) distance from treatment centre to home or working place
(viii) the type of psoriasis
4.3.1 Etretinate (Tigason)
Avoid using the medication in reproductive female in order to prevent pregnant patient receiving the drug which is teratogenic. Absolute contraception must be practised in some difficult case and this must be continued for two years after stopping the medication (because of high lipophilic property and long elimination half-life of 80 days). The newer acitretin was found to be of much shorter half life (elimination half-life of 50 hours) but because of some conversion back to etretinate was detected, its enthusiastic future is jeopardized.
Avoid treating patients with overt symptoms of ischaemic heart disease or patients that are at definite risk for developing atherosclerosis. Handle patients with preexisting hyperlipidaemia carefully, it is a relative contraindication. Dietary regulation and recommendations about increase physical activity should be given. Low fat, low calorie diet, avoidance of alcohol intake and increasing physical activity are effective in reduction of hyperlipidaemia induced by the drug. Hyperostoses can be induced after several years of continuous treatment with etretinate.
Minor side-effects are unavoidable and dose related. Dryness of the lips, nasal mucosa, eyes, mouth, throat or vagina, painful exfoliative cheilitis, urethritis, balanitis, gingivitis, peeling of finger tips and corneal ulceration, burning sensations in the skin, diffuse alopecia, epistaxis, widespread erythema will be present to various degree. Slight elevation of liver enzymes may be found. Toxic hepatitis may occur especially when it is combined with methotrexate. The long term adverse effect of hyperlipidaemia, hyperostosis resembling diffuse idiopathic skeletal hyperostosis (DISH) will be problematic in psoriatic patients on long term etretinate therapy.
The initial dose will be between 0.5 mg and 1 mg/kg/day. The response is very often dose related. Dose reduction is possible when it is used in combination with phototherapy or photochemotherapy. They are one of the most effective combination in clearing psoriasis. Etretinate alone seldom can control psoriasis perfectly and useful adjunctive therapy with phototherapy, PUVA, steroid cream will be very synergistic. It may also be used in generalized pustular psoriasis although methotrexate works as good or better.
Etretinate is indicated for moderate or extensive psoriasis, pustular psoriasis and psoriasis resistant and poorly controlled with all forms of topical therapy. Patient should be excluded for the following conditions before initiating treatment : liver disease, hyperlipidaemia, pregnancy or potential pregnancy, previous history of hypersensitivity to retinoid and history of elevated cerebrospinal fluid pressure. Monitoring with fasting lipid level and periodic liver function are required monthly initially and then every few months when stabilised.
4.3.2 Methotrexate
It is the magic drug for psoriasis provided adequate monitoring is provided. It is given as once weekly to once biweekly doses. An initial test dose of 2.5 mg was given and complete blood picture and liver function test should be monitored for few days before the full planned dose is given. Usually 7.5 to 25 mg per week as a single dose can be given according to body weight of patient and response of disease. Before initiating treatment, renal (renal function tests), hepatic function (history, liver function tests and if feasible a preliminary liver biopsy), and complete blood picture should be taken to ensure no contraindication. Peptic ulcer and infection must be treated before starting therapy. Impaired renal function must be accompanied by dose reduction. Continuous recording of the cumulative dose in a chart together with liver, marrow and renal function will be very helpful. Complete blood picture and liver function test should be taken regularly every month initially and then every 3 to 6 months for monitoring.
When the cumulative dose reach 1.5 to 2.0 gm, a liver biopsy must be done and this investigation at present is not replaceable other methods, e.g. hepatic or CT scan. Early fibrosis and cirrhosis found in biopsy are indications for stopping the therapy whereas fatty change and mild inflammatory changes can allow continual therapy if the condition is compelling. If patient refuse to have the liver biopsy, no more methotrexate should be given. For those who have normal result on liver biopsy, another cumulative dose of methotrexate of 1.5 to 2.0 mg reached before the second biopsy done to monitor the liver function. This usually takes 2 to 3 years.
Methotrexate is teratogenic and conception is not advised within 3 months of stopping treatment. Other side effects include : anaemia, leukopenia, anagen alopecia, cutaneous erosions, ulceration, reactivation of tuberculosis, septicaemia gastrointestinal bleeding, oligospermia, anorexia, nausea.
Despite all these side effects, methotrexate is highly effective for many forms of psoriasis and also psoriatic arthropathy. It is available as 2.5 mg tablets and injection form (for intramuscular injection).
4.3.3 5-Hydroxyurea
Hydroxyurea causes short term reversible marrow suppression and hence complete blood picture must be monitored closely. It is given from 500 mg daily to 1500 mg daily with a modest fall in haemoglobin expected. Mild GI upset may be associated. It is unfortunately not very effective in many psoriatic patients and it is of slow onset. The therapeutic effect may not be apparent after 2 months of therapy. It can be tried for patient with impaired liver function.
4.3.4 Cyclosporin A (Sandimmun)
This is a powerful medication. Improvement may be seen within few days with a dose of 3 mg/kg/day. If there is no improvement within 2 weeks, the dose may be increased by 0.5 to 1 mg/kg/day at a 2-weekly interval to a maximal dose of 5 mg/kg/day. Maintenance dose should be reduced to the smallest dose that allows adequate control.
The most important side-effects are dose related hypertension and nephrotoxicity. Hence blood pressure and renal function (creatinine clearance) should be closely monitored in the first few weeks, then monthly. Other side-effects include gum hyperplasia, hypertrichosis, acral paraesthesia or hyperaesthesia, tremor and dyspepsia.
Cyclosporin should not be given to patients with renal dysfunction, uncontrolled hypertension, past or present malignancy, acute infections, pregnancy, lactation and known hypersensitivity. Cyclosporin is expensive but this low dose regimen for psoriasis is the last resort for patients with resistant psoriasis to other therapies or contraindicated for one reason or another. Even if the patient can afford to purchase the medication himself, it should not be used indiscriminately because the theoretical risk of prolonged immunosuppression and the report of lymphoma (though very rare) associated with the medication.
4.4 Phototherapy and Photochemotherapy
4.4.1 UVB Phototherapy
Suberythemogenic doses given 2 to 3 times weekly can clear psoriatic lesions in a few weeks. The compliance of patient depends very much whether the patient can afford to spare time for this form of treatment. The power of Phototherapy unit varies one from the other. In old models, the irradiation time may well be over 10 to 20 minutes but newer models will deliver the MED (minimal erythema dose) within 100 seconds.
At the first visit, a test area is needed with increasing doses of UVB to find out the optimal doses. Usually the darker the skin, the greater dose is required for reaching the MED (similar the skin types in Caucasian). It has been estimated in the West temperate regions, the annual UVB dose an outdoor worker receives is 500 MEDs, while an indoor worker receives 200 MEDs. A psoriasis patient on maintenance therapy receives more than 700 MEDs. The long term life-time incidence of non-melanoma skin cancer in patients receiving long term UVB phototherapy is estimated to be three times to eight times that of normal. Long term follow up later in life is necessary in order to pick up skin cancer. The other side effects include pruritus secondary to xerosis, burnt and flare up of Herpes Simplex infection.
Emollient applied on the skin before irradiation will enhance the therapeutic effect and it will antagonize the drying effect of UVB phototherapy. Cumulative dosage of UVB should be recorded clearly in patient's record. The addition of etretinate will help to lower the dosage or frequency of UVB phototherapy. In pregnant psoriatic woman, phototherapy may be the best to control psoriasis and least effect on the fetus.
4.4.2 Goeckerman Regimen
This is mainly a regimen for in-patient or day care centre patient. It is a time-consuming but effective methods. The combination of rest, tar, phototherapy all contribute to the success of this form of therapy.
Patient is treated either in day care centre or dermatology wards. Experienced dermatologic nurse will be essential to carry out this form of therapy. 1% crude coal tar will be applied in the morning and again at afternoon. In the later part of morning, the residual tar is removed by bathing with Liquor Picis Carbonis and a suberythemogenic dose of UVB is administered, follow which the tar is reapplied. Tar is best applied with a paintbrush or a wooden spatula covered with layers of tubular cotton gauze. Dressings may be applied before the tar dries. No powder is needed. The removal of tar is best done by softening the tar with an application of coal tar and salicylic acid ointment, followed by the tar bath. The main complication of this treatment is folliculitis. Majority of the patient will have extensive plaque psoriasis cleared, thinned or controlled after 3 weeks treatment.
4.4.3 Ingram Regimen
It is similar to that of Goeckerman regimen except that 0.25 % Dithranol in Lassar Paste is applied instead of 1% crude coal tar. It is applied once daily usually after the UVB therapy. It is difficult to spread in applying the paste to the lesions. Since dithranol is a strong irritant and stains linen, accurate localization of the medication is needed to prevent burning of the normal surrounding skin which may be protected by using some barrier cream e.g. zinc cream surrounding the psoriatic lesions. It is not used in pustular psoriasis and unstable psoriasis. Dusting with talcum powder and covering with old nylon tights helps to prevent the spread of dithranol especially if a modern ointment form is used instead of the lasser paste product. Olive or mineral oil may be needed to remove the stiff paste before going to take the tar bath prior to UVB therapy. It has similar efficacy as that of Goeckerman regimen.
4.4.4 PUVA (Systemic and Topical)
0.6 mg/kg of 8-methoxypsoralen is taken orally by patient 2 hours before irradiation with UVA (320-400 nm). New model of PUVA machine can irradiate the whole body while patient has to stand. Old model machine can only radiate one side of body at a time but with the advantages that patient can lie down comfortably. Eye protection is important. During irradiation and after taking the drug that day, patient must wear UVA opaque goggles to prevent cataract and acute photosensitivity of the eyes. Patient is required to have treatment at the day care centre two to three times a week. The initial dose can be 2 J/cm² and then step up the dosage by 0.5 J/cm² each visit till the optimal dose is reached which may be as high as 8 to 15 J/cm². Usually 15 to 25 treatment will complete one course and maintenance treatment can be given with weekly or biweekly PUVA for 3 more months. If the psoriasis remains quiet, it can be managed with topical therapy only. In later phase, if there is flare up of condition, a new course will be given again. The duration to complete each course will require 2 to 3 months. When cumulative dose of 2000 J/cm² reached, PUVA is usually not advised to be continued because of the risk of skin cancer after the high cumulative dose will rise substantially by 13 folds. Patients with cutaneous malignancy potential are excluded for PUVA e.g. Arsenic ingestion, radiotherapy. PUVA is of value in generalized pustular psoriasis, erythrodermic psoriasis, chronic palmo-plantar pustular psoriasis.
The topical PUVA can be given applying similar principle except that the psoralen is given not in oral form but in the form of topical lotion (the Meladinine Paint) which is particularly convenient for local palm and sole psoriasis. However, phototoxic reaction is more common. The UVA is given as soon as 10 to 15 minutes after the application of the paint. It is commonly used to treat Vitiligo which is limited to the face. Very extensive application of the 8-MOP paint is not advisable because of the phototoxic effect and absorption of enough 8-MOP requiring protection of the eyes as in systemic PUVA. However, topical PUVA require no systemic medication and patient with gastrointestinal upset of 8-MOP will tolerate topical PUVA and smaller dose of UVA delivered with fewer side effects to normal skin.
The adverse effects of PUVA are : Erythema, nausea, pruritus, gross freckling (PUVA lentigines), hyperpigmentation, onycholysis, cataract, increase non-melanoma skin cancer risk, cutaneous pain, precipitate photosensitive condition such as lupus erythematosus, reduction of delayed hypersensitivity and flare up of herpes.
4.5 Conclusion in the Treatment Modalities
The commonest form of treatment for mild psoriasis is topical steroid. For moderate plaque type psoriasis, the topical therapy is usually an adjunctive therapy and the combination of etretinate and phototherapy or photochemotherapy usually have the best result. For severe cases, admission to hospital is necessary for management because bed rest and away from work can already lead to more stable condition. Moreover, the trial of in-patient regimen will work at most time. The last resort is Cyclosporin A. All the systemic therapies have to some extent harmful to the body. They should be selected and supervised by experienced dermatologists. Systemic steroid is very effective in controlling psoriasis but it is deliberately not listed because it will do more harm than good in the long term management. Very often, you may find that there are more problems than before when starting a psoriatic patient with systemic steroid. However, systemic steroid will be given for the poorly controlled pustular psoriasis of pregnancy, life threatening erythrodermic or generalized pustular psoriasis. This should only be given in in-patient under the supervision and advice of consultant dermatologist.
5. OTHER TREATMENTS
There are some other forms of treatment for psoriasis not practised in Social Hygiene Service. They are not used because they are either not gaining consistent results or their limited experience with one or two reports of success or requiring special treatment facilities. Some of the initial improvement may be solely placebo effect. These are mentioned because they signifies how disappointing the treatment to some form of psoriasis and that we are always trying to seek new treatment breakthrough for psoriasis.
The treatment of psoriatic nail do place a dilemma for dermatologists. Intralesional corticosteroids injecting to the nail matrix may control some nail dystrophy but it is painful and the control is not complete and not always successful. Avulsion of grossly deformed nail will not correct the deformity. Occasionally, methotrexate or PUVA for extensive psoriasis may also improve the nail.
Topical treatment : Occlusive dressings with hydrocolloid dressings.
Systemic treatment : Sulphasalazine, ketoconazole, acitretin, Fumaric acid, Fish Oil supplements, Zinc sulphate, Piritrexim, Razoxane (withdrawn because of increase incidence of acute myeloid leukaemia), Azathioprine, Colchicine, Antibiotics, Piritrexim (withdrawal because of unexpected high incidence of liver damage), rifampicin, propylthiouracil, benoxaprofen, topical lonapolene, azaribine and zidovudine for AIDS associated psoriasis.
Selective UVB phototherapy (UV sources with peak effective output in the 300 - 320 nm range) : Psoralen-311 nm therapy : a narrow-band UVB source emitting 311 nm (compared with conventional PUVA : peak emission at 352 nm) are shown to be effective. The 311 nm UVB phototherapy alone is also effective. This source of UVB light has avoided the non-therapeutic but erythemogenic UVB (of wavelengths of less than 300 nm). Low intensity selective UVB phototherapy (LISUP) has been designed for home use but they are probably less effective than conventional phototherapy. The Dead Sea Clinic treatment (helio-therapy) is basically a form of phototherapy : sun exposure followed by bathing in mineral rich sea. (It is claimed to be cost effective and pleasant treatment; resulting in some Scandinavian countries preferring to fund Dead Sea Therapy over the expensive in-patient care for chronic psoriatics.)
Others : Alternative medical treatment such as acupuncture, dietary manipulation programmes, biofeedback, Chinese herbal treatment, homeopathic remedy. Dialysis, Extracorporeal photophoresis, Cryotherapy, carbon dioxide laser, dermabrasion, Grenz ray therapy.
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