What is Psoriasis?
Psoriasis is a common systemic, genetic, and inflammatory disease of the skin affecting about 2% of general population. It is a long lasting and non-contagious disorder that occurs when the body’s immune system sends false signals to skin cells to grow and multiply faster than normal. When these excess cells accumulate on the surface of the skin, they begin forming red and flaky patches that are typical of psoriasis.
Different types of psoriasis include:
Plaque: This is the most common type of psoriasis. It presents itself as red and raised patches of the skin and is often covered with white flaky coats and appears on the scalp, elbow, knee and lower back. Plaque psoriasis is usually accompanied by uncomfortable itching which makes it worse.
Inverse: Psoriasis of the armpit, genital, growing, or buttocks. It appears as red and raw patches on the skin with minimal flakes.
Erythrodermic: Psoriasis that affects the largest area of the skin on the body and appears bright red. It may cause severe itch, pain, an increase in heartbeat, and fever requiring emergency care.
Pustular: Psoriasis that occurs as a result of excess neutrophils on the outer surface of the skin. It is characterized by red swollen/pus-filled bumps on palms of the hands or soles of the feet. If pustular psoriasis is accompanied by fever and affects a wide area of the skin, immediate care is required.
Guttate: Psoriasis often caused by an illness such as strep throat and appears as small red spots on arms, legs, buttocks and even on the scalp, ear or face. It may either occur in people with no history of psoriasis or people who previously were diagnosed with plaque psoriasis.
Biologic Drugs Used in Treatment of Psoriasis
To relieve the uncomfortable symptoms and improve a patient’s quality of life there are a number of different recommended treatments available including biologic drugs. Biologic agents used for psoriasis are proteins manufactured through biotechnology using recombinant DNA technology. They are antibodies that are medically beneficial in treating many diseases by directly targeting components of the immune system.
Also Read: Otezla (apremilast) Cost, Prescribing Information for Psoriasis, Dosage, Side Effects
Biologic drugs affect the immune system through different mechanisms:
Biologic drugs like Raptiva (alefacept) block the action or production of specific immune cells called T cells (white blood cells) or T-lymphocytes. T cells are activated in response to foreign substances invading the body. When activated T cells accumulate on the skin they cause inflammation and other symptoms of psoriasis. Therefore, biologic agents that inhibit the activation of T cells will inhibit initiation of the psoriasis cycle.
Some biologic drugs block the action of cytokines such as tumor necrosis factor-α (TNF-α). Cytokines like TNF-α are small proteins that stimulate the immune response and contribute to inflammation. Anti-TNF agents such as Humira (adalimumab), Enbrel (etanercept), and Remicade (infliximab) bind to TNF-α and inhibit inflammation.
Other biologic agents block the action of cytokines such as interleukins (IL) 12, 23, and 17A. Interleukins are proteins produced by white blood cells (T lymphocytes). IL 12, 23, and 17A are involved in immune and inflammatory responses. Agents in this class such as Stelara (ustekinumab), bind to IL 12 and 23 blocking their ability to cause inflammation and other symptoms of psoriasis.
Next: T-Cell, TNF-Alpha Inhibitors