What is hidradenitis suppurativa? Hidradenitis suppurativa is a skin disease that causes pimple-like bumps or boils on and under the skin. The disease is chronic (long lasting) and can be painful. HS does not spread from one person to another. HS starts in the hair follicle in the skin and happens where areas of skin may touch or rub together. Poor personal hygiene habits, such as not bathing or shampooing your hair, do not cause HS. In most cases, the cause of the disease is unknown.
What is ichthyosis? Ichthyosis is a group of skin disorders. It leads to dry, itchy skin that appears scaly, rough, and red. The symptoms can range from mild to severe. Ichthyosis can affect only the skin, but sometimes the disease can affect internal organs, too.
What is alopecia areata? Alopecia areata is a disease that causes hair loss. In alopecia areata, the immune system attacks the structures in skin that form hair (hair follicles). Alopecia areata usually affects the head and face, though hair can be lost from any part of the body. Hair typically falls out in small, round patches about the size of a quarter. In some cases, hair loss is more extensive.