Sycosis Vulgaris and Furunculosis

Furunculosis / Boils

• A boil is an acute, round, tender, and circumscribed follicular staphylococcal abscess that generally ends in central suppuration.
• A carbuncle is two or more confluent furuncles with separate heads.
• Predisposing factors for boils include:
  • Impaired skin surface integrity due to irritation, friction, hyperhidrosis, dermatitis, or shaving.
  • Presence of a contagion or autoinoculation from a carrier focus, usually in the nose or groin.
  • Systemic disorders such as malnutrition, blood diseases, diabetes, or AIDS.
• Boils occur in hair follicles and may continue for a prolonged period by autoinoculation.
• Lesions may disappear before rupture, but most undergo central necrosis and rupture through the skin, discharging purulent, necrotic debris.
• Commonly affected sites include the face, neck, arm, wrist, fingers, buttocks, and anogenital region.
• Treatment for boils involves topical and systemic antibiotics, as well as incision and drainage of some cases.

Cellulitis and Erysipelas

• Cellulitis is an infection of the subcutaneous tissue.
• Erysipelas is more superficial, involving the dermis and upper subcutaneous tissue.
• Both conditions are caused mainly by Streptococcus pyogenes.
• Clinical features of cellulitis and erysipelas include:
  • Erythema, heat, swelling, and pain or tenderness.
  • In erysipelas, the edge of the lesion is well-demarcated and raised, while in cellulitis it is diffuse.
  • Blistering and hemorrhage are more common in erysipelas.
  • Lymphangitis and lymphadenopathy are frequent.
• The face and legs are the most frequent sites affected.
• Unusual complications include gangrene, metastatic abscesses, and grave sepsis.
• Treatment involves systemic penicillin and cephalosporins.

Erythrasma

• Erythrasma is a mild, chronic, localized superficial infection of the skin.
• It is more common in adults.
• Etiology is Corynebacterium minutissimum.
• Predisposing factors include a warm and humid climate, and diabetes mellitus.
• Clinical features include:
  • Patches (sharply marginated, dry, brown, and slightly scaling) in intertriginous areas.
  • Coral red fluorescence on Wood's light examination.
• Treatment involves topical azole antifungals or oral erythromycin in extensive cases.

Ecthyma

• Ecthyma starts as non-bullous impetigo but develops into a punched-out necrotic ulcer.