Chronic deep bacterial folliculitis

**Definition:** A chronic pyogenic infection by Staphylococcus aureus involving the whole depth of the hair follicle. Sycosis occurs mostly in males after puberty, and commonly involves the follicles of the beard. Most cases begin in the third or fourth decade. Unknown host factors appear to be important in the chronicity of the infection. Extensive follicular destruction and scarring may ensue (lupoid sycosis).