Variants

• tropical - affects young caucasians in hot, humid climates such as the Far East. The trunk is often affected. The lesion may be resistant to all treatment other than return to a temperate climate.
  
  
• steroid - affects patients on systemic steroid therapy. The trunk is usually affected. Comedones are typically absent. It may be a presenting feature of Cushing's syndrome.
  
  
• chemical - due to contact with cutting oils or chlorinated hydrocarbons. Atypical sites eg. the leg, may be affected.
  
  
• fulminans - is a sudden severe inflammatory reaction associated with fever, general malaise, polyarthralgia, a leucocytosis and an elevated ESR. It requires urgent referral (1)
• neonatorum - a rare form seen in young male infants.

Some clinical variants may require special management:

• acne conglobata - a severe form of acne which can cause severe scarring ¢ acne fulminans
• acne excoriée - psychological or emotional condition which can be seen in young women. It is characterised by self inflicted wounds. ¢ acne mechanica - caused by pressure, friction, or rubbing
• acne cosmetica - caused due to contact of the skin with comedogenic products. Refraining from these products is advised ¢ chloracne - several large comedones caused by occupational exposure to halogenated hydrocarbons can be seen in this variant
• gram negative - associated with prolonged antibiotic use. It can be difficult to treat

Reference:

• 1. Clinical Knowledge Summaries 2006.Acne Vulgaris