What does a Staphylococcus skin infection look like?

Clinical Appearance of Staphylococcus Skin Infections

Staphylococcal skin infections present with distinct purulent (pus-forming) lesions that differ fundamentally from the diffuse spreading redness of streptococcal infections. 1

Key Visual Characteristics

Impetigo (Staphylococcal Type)

• Bullous lesions that begin as superficial vesicles, rapidly enlarging into flaccid bullae filled with clear yellow fluid that later becomes darker and turbid 1
• Ruptured bullae leave a thin brown crust resembling lacquer 1
• Discrete purulent lesions, often multiple, typically on exposed areas like face and extremities 1
• Lesions characterized by pustules with a narrow rim of erythema surrounding them 2

Furuncles (Boils)

• Inflammatory nodules with overlying pustules through which hair emerges 1
• Infection extends through dermis into subcutaneous tissue forming a small abscess 1
• Can occur anywhere on hairy skin 1
• When multiple adjacent follicles coalesce, forms a carbuncle - a larger inflammatory mass with pus draining from multiple follicular openings 1

Cutaneous Abscesses

• Painful, tender, fluctuant red nodules 1
• Surrounded by a rim of erythematous swelling 1
• Contain collections of pus within dermis and deeper skin tissues 1

Critical Distinguishing Features from Streptococcal Infections

Staphylococcal infections produce localized purulent lesions, while streptococcal infections cause diffuse spreading inflammation without pus collections. 3 This distinction is clinically crucial because:

• Staphylococcal infections require drainage as primary treatment, with antibiotics playing a subsidiary role 1
• Streptococcal cellulitis requires antibiotics as primary treatment 1

What Staph Does NOT Look Like

• NOT diffuse spreading erythema with poorly demarcated borders (that's streptococcal cellulitis) 1, 4
• NOT sharply demarcated raised borders with intense uniform redness (that's erysipelas, almost exclusively streptococcal) 5, 4
• NOT "orange peel" (peau d'orange) appearance - this dimpling pattern indicates streptococcal infection 1

Common Locations

• Face and hair follicles are most commonly affected 2
• Carbuncles particularly favor the back of the neck, especially in diabetic patients 1
• Can occur on any hairy skin surface 1

Associated Features

• Minimal surrounding cellulitis unless infection is severe 1
• Intense cellulitis surrounding lesions suggests a virulent, penicillin-resistant strain 2
• Regional lymphadenitis may occur, but systemic symptoms usually absent in uncomplicated cases 1
• Bullae and pustules are the hallmark, not vesicles with clear fluid 1, 2

Clinical Pitfall to Avoid

Do not confuse purulent staphylococcal infections with non-purulent cellulitis. 1 The term "cellulitis" should never be applied to infections with pus collections like abscesses or furuncles - this leads to incorrect treatment with antibiotics alone when drainage is actually needed 1. If you see pus, think staph and think drainage first 1.