Introduction
Psoriasis is a chronic genetically influenced immunologically based inflammatory disease of skin and joints. A majority of patients can be managed with topical coal tar, Dithranol and corticosteroids. However, psoriasis has a tendency to recur and may become worse. Moderate to severe psoriasis defined as more than 20% or more body surface area or patient unresponsive to topical therapy are termed as difficult psoriasis.
Types of Difficult Psoriasis
- Psoriatic erythroderma means psoriatic lesions involving more than 90% body surface area.
- Pustular psoriasis, psoriatic plaques developed with pus filled lesions.
- Psoriatic arthritis.
- Palmoplantar and scalp psoriasis.
- Plaque psoriasis not responding to conventional therapy.
How to Assess Psoriasis Patients?
The patient presenting with psoriasis requires a welcoming and sympathetic approach. To understand their condition and aggravating factors, the overall assessment, including patient perception and expectation, life style, other diseases and drugs should be made. Also, previous treatment and their effectiveness and side effects have to be assessed.
Factors Causing Exacerbation of Psoriasis
Stress, alcohol, smoking, trauma, sun, oral corticosteroids, beta blockers, Lithium, drugs used to treat malaria, painkillers, etc.
Treatment
1) Scalp Psoriasis:
Scalp to be drenched overnight with coconut oil based coal tar and salicylic acid pomade and cover with a shower cap or polyethylene cap. Shampoo the hair only the next morning and use a comb to remove the scales in the scalp. Use potent steroid lotion daily or intermittently. Narrow band UVB (ultraviolet B) is also very effective in scalp psoriasis.
2) Palmoplantar and Pustular Psoriasis:
Topical PUVA (psoralen and ultraviolet A radiation) is the most effective in palmoplantar psoriasis. PUVA usually leads to clearing and may produce long-lasting remissions. For pustular psoriasis, Acitretin is the drug of choice. The usual dose given is 1 mg/kg/day.
3) Psoriatic Arthropathy:
In this type, Methotrexate is the drug of choice. Biologics will also play a role in psoriatic arthritis.
4) Psoriasis in Pregnancy:
Psoriasis in pregnancy is usually managed by topical therapies. Generalized pustular psoriasis of pregnancy is best treated with oral Prednisolone. Cyclosporine is claimed to be compatible with pregnancy, but safety is not established.
5) Psoriasis in Children:
Retinoid appears to be the drug of choice for children, 0.25 to 0.6 mg/kg is the recommended dose. Monitoring with bone scan every 12 to 18 months is recommended for children on retinoid.
