Furuncle is an acute infection of hair follicles with Para follicular inflammation. It commonly occurs over the axillae, back of the neck and buttocks. Poor hygiene, immune suppressive diseases and irritation are known contributing factors. The causative agents are Staphylococci aureus. It is therefore not found on the hairless palm or sole, but is usually encountered where the skin is hairy, injured by friction or is dirty and macerated by sweat.
Occasionally, a furuncle may be the primary source of a Staphylococcal septicaemia and may be responsible for osteomyelitis, perinephric abscess or empyema, particularly in debilitated patients. A boil on the face may be complicated by a pyelophlebitis spreading along the facial veins resulting in thrombosis of the cavernous sinus.
Hidradenitis suppuritiva . Multiple infected foci in the axillae or groins due to infection of the apocrine sweat glands of these regions are usually misdiagnosed as boils. They do not respond to antimicrobial therapy and can only be treated effectively by excision of the affected skin; if this is extensive, the defect may require grafting.
- There is an intense local irritation of acute onset
- Painful firm, reddish, round swelling initially, which later becomes fluctuant
- Suppuration and central necrosis occurs later
- The condition subsides and is self-limited to recur in multiple lesions (chronicity)
- It may subside spontaneously without suppuration (Blind boil)
- Incision /Excision if complicated