Hidradenitis suppurativa

Hidradenitis suppurativa (HS), also known as acne inversa, is a long term skin disease characterized by the occurrence of inflamed and swollen lumps. These are typically painful and break open releasing fluid or pus. The areas most commonly affected are the underarms, under the breasts, and groin. Scar tissue remains after healing. Self-consciousness or depression may result. Hidradenitis suppurativa (HS), also known as acne inversa, is a long term skin disease characterized by the occurrence of inflamed and swollen lumps. These are typically painful and break open releasing fluid or pus. The areas most commonly affected are the underarms, under the breasts, and groin. Scar tissue remains after healing. Self-consciousness or depression may result. The exact cause is usually unclear but believed to involve a combination of genetic and environmental factors. About a third of people with the disease have an affected family member. Other risk factors include obesity and smoking. The condition is not infectious, related to hygiene, or to the use of deodorant. The underlying mechanism is believed to involve either a dysfunction of apocrine sweat glands or hair follicles. Diagnosis is based on the symptoms. There is no known cure. Warm baths may be tried in those with mild disease. Cutting open the lesions to allow them to drain does not result in significant benefit. While antibiotics are commonly used, evidence for their use is poor. Immunosuppressive medication may also be tried. In those with more severe disease laser therapy or surgery to remove the affected skin may be carried out. Rarely a skin lesion may develop into skin cancer. It is estimated to affect between 1% and 4% of people. Females have the condition about three times more often than males. Onset is typically in young adulthood and may become less common after 50 years old. It was first described some time between 1833 and 1839 by Alfred Velpeau. The cause of HS remains unknown and experts disagree over proposed causes. The condition probably results from a combination of genetic and environmental factors. Lesions occur in any body areas with hair follicles, although areas such as the axilla, groin, and perianal region are more commonly involved. This theory includes most of the following potential indicators: The historical understanding of the disease suggests dysfunctional apocrine glands or dysfunctional hair follicles, possibly triggered by a blocked gland, create inflammation, pain, and a swollen lesion. Several triggering factors should be taken into consideration: Some cases have been found to result from mutations in the NCSTN, PSEN1 or PSENEN genes. The genes produce proteins that are all components of a complex called gamma- (γ-) secretase. This complex cuts apart (cleaves) many different proteins, which is an important step in several chemical signaling pathways. One of these pathways, known as Notch signaling, is essential for the normal maturation and division of hair follicle cells and other types of skin cells. Notch signaling is also involved in normal immune system function. Studies suggest that mutations in the NCSTN, PSEN1, or PSENEN gene impair Notch signaling in hair follicles. Although little is known about the mechanism, abnormal Notch signaling appears to promote the development of nodules and lead to inflammation in the skin.