Sycosis Vulgaris and Furunculosis

Boils and Furunculosis

• 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 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.

Clinical Picture and Treatment of Boils

• Lesions begin in hair follicles and often continue for a prolonged period by autoinoculation.
• Some lesions disappear before rupture, but most undergo central necrosis and rupture through the skin, discharging purulent, necrotic debris.
• Commonly involved sites are the face, neck, arm, wrist, fingers, buttocks, and anogenital region.
• Treatment includes topical and systemic antibiotics, as well as incision and drainage of some cases.

Cellulitis and Erysipelas

• Cellulitis is an infection of the subcutaneous tissue, while erysipelas is more superficial, involving the dermis and upper subcutaneous tissue.
• Both are caused mainly by Streptococcus pyogenes.
• Clinical features of erysipelas include:
  • Well-demarcated and raised edges of the lesion.
  • Blistering and hemorrhage are more common.
  • 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 typically 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 picture includes:
  • Patches that are sharply marinated, dry, brown, and slightly scaling in intertriginous areas.
  • Coral red fluorescence on Wood's light examination.
• Treatment includes topical azole antifungals and oral erythromycin in extensive cases.

Ecthyma

• Ecthyma is a type of bacterial infection caused by Streptococcus.

Common Bacterial Infections

• Common staphylococcal infections include folliculitis, furunculosis, carbuncle, and impetigo.
• Common streptococcal infections include erysipelas, cellulitis, impetigo, and ecthyma.

Impetigo

• Definition: Impetigo is a contagious superficial pyogenic infection of the skin caused by staphylococci and streptococci.
• It is a mixed staphylococcal and streptococcal infection that affects neonates.