KOCHI: World Psoriasis Day is observed on the 29th of October every year to create awareness of the disease, understand its nature and therefore improve all-round management of the disease.
Psoriasis is a dermatological problem characterised by red scaly raised patches on the skin. It is an immune-mediated disorder. When the body is attacked by bacteria, viruses and other foreign proteins, the immune system of the body reacts with a protective response called inflammation. This serves to destroy the invaders and also to rebuild injured tissue. In the person who has psoriasis, the immune system triggers off an inappropriate inflammation and there is an accelerated growth of skin cells which is seen as red scaly patches.
How does psoriasis present?
Psoriasis can occur anywhere in the skin including face, scalp, folds and palms and soles. The scaly patches may be of plaque type which is the most common presentation. Sometimes it may appear as red drop like patches (guttate psoriasis) or occur only in the folds (inverse psoriasis), or as tiny pus filled boils (pustular) and rarely as erythrodermic psoriasis. Erythrodermic psoriasis is an uncommon type of psoriasis where more than 90% of the body surface area will appear fiery red and scaly. There is severe itching and pain and the condition is life threatening. Immediate medical attention is then necessary. Psoriasis can also affect the joints (psoriatic arthritis) causing pain and swelling and difficulty in movement.
Treatment Psoriasis can be mild (<3% body surface area), moderate (3-10%) or severe (>10%) depending on the extent of skin involved.
The chronic nature of psoriasis means long-term management involving periodic visits to your dermatologist, understanding the nature of the disease and therefore co-operation with the doctor.
Recent advances have especially helped those with moderate to severe disease. The existing treatment options are:
Topical medications
Topical treatments are creams applied to the skin and are usually used as first line of treatment in mild psoriasis or used in combination with internal medicines in moderate to severe disease. The most commonly used topical steroid creams help in reducing inflammation. The other creams are calcipotriene (a synthetic vitamin D3 derivative), calcipotriene combined with steroid (betamethasone dipropionate), tazorotene (a vitamin A derivative), anthralin and tacrolimus (calcineurin inhibitor) which is a non steroid anti-inflammatory agent.
Phototherapy
This is carefully measured light therapy which involves exposure of the skin to ultraviolet light. Narrow band ultraviolet B (UVB) light penetrates the skin and slows the growth of affected skin. The major drawback of phototherapy is that the patient will have to travel at least twice per week to the hospital where the phototherapy units are present.
Systemicmedications
These are drugs that are prescribed orally for the treatment of psoriasis. The most common drugs are acitretin, methotrexate and cyclosporine. Acitretin is an oral derivative of vitamin A. It takes a long time for the drug to start acting so you may have to wait patiently till around 8-16 weeks. This medicine is avoided in females of child bearing age as severe birth defects can occur. Methotrexate is an antimetabolite frequently used in psoriasis. The major side effects are bone marrow and liver toxicity. So your dermatologist will monitor you frequently especially during the initial months of treatment. Cyclosporine is an immunosuppressive drug used in the treatment of severe psoriasis. It can provide rapid relief from symptoms and improvement can be seen in 2 weeks.
Biologicals
A biologic is a protein based drug derived from living cells cultured in a laboratory. These drugs target specific parts of the immune system. They are quite expensive. They block certain strong inflammatory mediators which are responsible for the development of psoriasis such as TNF a (tumor necrosis factor alpha) that are acted upon by etanercept and infliximab and interleukins 12 and 23 that are dealt by drugs like ustekinumab . These drugs also suppress our immune system and our ability to fight infections.
Tests you may have to do
Your dermatologist will ask for some tests after a complete clinical examination. Some basic investigations include blood tests, urine analysis, chest X ray, ultrasound of the abdomen. Thorough screening for infections before starting internal medicines is essential. The number of tests and nature of investigations will also depend on various factors of each patient such as age, presence of diabetes, obesity, hypertension, previous treatment for tuberculosis or any other coexisting medical condition.
Lifestyle modifications
Once thought of as merely a skin disease it is now recognised as being associated with a number of other illnesses referred to as comorbidities. These include cardiac diseases, lipid abnormalities, hypertension and diabetes all of which carry a great risk of increased mortality compared to psoriasis alone. There is increasing stress on comorbidities nowadays as it has been found that treatment of comorbidities is a part of management of psoriasis.
Another point is life style modifications. This is an important responsibility of patients. Regular exercising, loss of excess weight, stopping smoking and abstinence from alcohol are crucial contributions of the individual towards treatment. Stress can worsen psoriasis but stress is a part of modern life.
Dr M Shraddha MD, DNB, PhD
consultant dermatologist Apollo Hospitals, Greams Road &Apollo Medical Centre, Koturpuram Chennai