What skin diseases can cause itching?
Many skin diseases can be the cause of itching. The main skin diseases that cause pruritus are frequent inflammatory dermatoses:
Eczema
Eczema is characterized by the presence of red plaques, dry skin and itching. There are several types of eczema, the most common of which are atopic eczema, contact eczema and chronic hand eczema.
Psoriasis
Psoriasis is characterized by the presence of more or less extensive red plaques, generally pruritic and covered with a thick layer of white scales.
Seborrheic Dermatitis
Seborrheic dermatitis affects the skin and/or scalp. It is defined by the presence of poorly defined red plaques covered with small, more or less greasy, non-adherent scales. Here again, pruritus is often very present and poses a daily problem.
Hives
Hives, or urticaria, is the appearance of mobile, red, raised and itchy patches. Hives is considered acute when it lasts less than 6 weeks, and chronic beyond that. There are many causes of hives, both allergic and non-allergic.
Other less common skin diseases are also associated with pruritus:
- Ichthyosis: a rare genetic disease in which the skin is very dry, rough and scaly.
- Bullous pemphigoid: an bullous autoimmune disease that affects the elderly.
Many infectious dermatoses cause pruritus:
- Scabies: a highly contagious parasite caused by a mite, the itch mite, which digs microscopic grooves into the skin. Pruritus is often intense and becomes worse at night.
- Lice: head lice are the most well-known kind, but there are also body lice and pubic lice.
- Chickenpox: probably the most well-known childhood disease. It is viral in origin and extremely contagious.
Skin allergies are another relatively significant category of dermatological pruritus. One can be allergic to metals such as nickel (particularly present in costume jewelry), perfumes, dyes, preservatives, etc.
Finally, dematological pruritus can result from more isolated skin afflictions such as insect stings or bites, reactions to certain plants, or sunburn.
In cases of pruritic dermatosis, the challenge is not scratching the lesions in order to avoid superinfections of the skin and/or healing wounds.