What is follicular occlusion syndrome?
Follicular occlusion syndrome refers to a group of diseases in which hair follicles become blocked with keratin (scale) and then rupture, resulting in inflammatory skin disease. These conditions commonly coexist. They may be severe and difficult to treat. Three of these diseases are together known as the follicular occlusion triad.
Hidradenitis suppurativa (acne inversa)
Acne conglobata (severe nodulocystic acne)
Dissecting cellulitis (perifolliculitis capitis abscedens et suffodiens)
A fourth condition, pilonidal sinus or pilonidal disease, makes up the follicular occlusion tetrad.