Psoriasis

Psoriasis

Psoriasis is a chronic inflammatory skin disease, believed to result from a combination of genetic factors and abnormalities in the immune system. Various factors contribute to the development and triggering of the disease, such as scratching, friction, infections, or medications. Psoriasis affects approximately 2% of the global population. One in three patients may experience nail abnormalities and joint pain. The disease is most common in people aged 20-30 years and 50-60 years, affecting both men and women, with women developing it earlier.

Factors that trigger the disease include scratching, friction, pressure, infections, certain medications, pregnancy, alcohol consumption, and severe sunburn.

Clinical features

Psoriasis presents as well-defined red patches with thick, silvery-white scales (silvery scale). The scales adhere quite firmly, and when removed, small bleeding points (Auspitz sign) may be visible. Rubbing the skin may induce new lesions in the area (Koebner's phenomenon). Commonly affected areas include the scalp, elbows, knees, buttocks, and shins. In severe cases, the rash may spread all over the body.

There are various forms of psoriasis. The most common form presents as thick, well-defined patches covered by firmly adhered white scales, which may be scattered all over the body, including the scalp and hairline. The size of the patches is variable.

Other types of lesions that may be seen include small, scattered (guttate) lesions, pustules, and rashes in body folds.

Nail abnormalities may include thickening of the nails (subungual hyperkeratosis), pitting, nail separation or detachment (distal onycholysis), and yellow discoloration (oil spot).

Some types of psoriasis may present with lesions in the mouth.

Joint pain occurs in 5-30% of chronic cases, often affecting the distal joints of the fingers or resembling rheumatoid arthritis.

Causes

The exact cause is still unclear, but it is believed to result from a combination of genetic factors and external environmental triggers. This leads to a rapid cell division of skin cells, causing thickening and rapid shedding of skin cells, resulting in thick patches and abundant loose scales. Another contributing factor is the abnormality of T-lymphocyte white blood cells, which causes the release of various substances that lead to inflammation in the skin.

Treatment

Psoriasis is a chronic disease with no cure, so the most important aspect of treatment is the patient's self-care to prevent or minimize flare-ups.

1. Factors that can worsen the disease include infections (such as bacterial infections of the upper respiratory tract), stress, certain medications (such as chloroquine, beta-blockers, alcohol, and lithium), scratching or rubbing, or skin wounds.
2. Oral vitamin A derivatives, such as acitretin, may be used in conjunction with light therapy. When used alone, they are typically reserved for severe cases or those with pustular psoriasis. Significant side effects include dry, peeling skin, elevated blood lipid levels, and liver enzyme abnormalities. This drug is contraindicated for pregnant women and should not be used for at least two years after discontinuation before attempting pregnancy.
3. Methotrexate is an effective and affordable treatment but has high side effects such as liver inflammation, elevated liver enzymes, and possible liver scarring. It is typically chosen for patients unresponsive to other treatments or safer alternatives. Therefore, blood tests should be performed regularly before, during, and after treatment.
4. Cyclosporin is used for severe cases due to its side effects, such as high blood pressure, kidney, and liver inflammation.
5. Other drugs: Currently, there are newer drug classes that show promising results, but they can be expensive and have side effects that still require further study and monitoring.

Since psoriasis is a chronic disease, medication use may sometimes cause side effects. Therefore, it is recommended to alternate medications periodically to avoid long-term side effects from using one drug consistently. In some cases, multiple drug classes may need to be combined, including topical and oral medications, to enhance treatment efficacy and reduce side effects.