Some patients have severe, aggressive forms of acne which merit separate discussion. These include acne conglobata, acne fulminans, Gram-negative folliculitis, pyoderma faciale and vasculitic acne. Notes on their treatment are included here.
Acne conglobata is a chronic and severe form of acne vulgaris characterized by burrowing abscesses and irre-gular scarring. The lesions may be associated with sinuses, necrosis and granulomatous inflammation. Males are more affected than females and the onset is usually between the ages of 18 and 30 years.
Acne conglobata may develop by the sudden deterioration of existing active papular or pustular acne or may be the recrudescence of acne quiescent for many years. The precise cause of acne conglobata is unknown; changes in reactivity to Propionibactenum acnes may be important.
Blackheads are a conspicuous feature and classically they appear in pairs or groups on the neck or trunk. Indeed they may even extend to involve the upper arms or buttocks. Inflammatory nodules form, usually in relation to multiple comedones, gradually increasing in size and breaking down to discharge pus.
As the nodules break down, crusts may form over an indolent deep ulcer which extends centrifugally the antigen patterns of acne conglobata patients was observed.
Because of the extent and severity of acne conglobata, patients should be offered isotretinoin. If it is not available, high doses of tetracycline or erythromycin 0.5 g/day) should be given, plus topical therapies such as alternate use of retinoic acid and benzoyl peroxide. Physical extraction of comedones will help, as will intralesional injection of triamcinolone into the larger inflamed cysts.
A very rare complication of acne conglobata is squamous cell carcinoma. Of six members in one family with acne conglobata, two developed large, aggressive and well-differentiated squamous cell carcinomas with-in their disease.