What is the name of the rash under a pannus?

Intertrigo: The Rash Under a Pannus

The rash under a pannus (skin fold) is called intertrigo, which is a superficial inflammatory dermatitis occurring where two skin surfaces touch and rub against each other, creating friction, moisture, and poor ventilation. 1

Clinical Characteristics

• Intertrigo appears as erythematous (red), macerated skin with peripheral scaling in areas where skin surfaces oppose each other, such as under the pannus (abdominal fold) 1
• The condition is exacerbated by moisture, heat, and lack of air circulation, making obesity-created skin folds particularly susceptible 2
• Symptoms often include itching, burning, pain, and unpleasant odor, which can significantly decrease quality of life 3

Common Secondary Infections

Intertrigo frequently becomes complicated by secondary infections due to the warm, moist environment:

• Candidal infections - Most common secondary infection, presenting with characteristic satellite pustules or papules beyond the main border of the rash 1
• Bacterial infections - Common pathogens include:
  • Group A beta-hemolytic streptococcus
  • Corynebacterium minutissimum (causes erythrasma)
  • Staphylococcus species 1

Diagnosis

• Diagnosis is primarily clinical, based on the characteristic appearance of erythema in opposing skin surfaces 1
• For candidal infections, potassium hydroxide (KOH) preparation can confirm the diagnosis by revealing pseudohyphae and budding yeast 1
• Wood's lamp examination may help identify certain bacterial infections (particularly erythrasma caused by Corynebacterium, which fluoresces coral-red) 1

Management

Prevention Strategies

• Minimize moisture and friction in skin folds using:
  • Absorptive powders (e.g., cornstarch)
  • Barrier creams or ointments 2
• Wear light, non-constricting, absorbent clothing; avoid synthetic fibers and wool 2
• Thoroughly dry skin folds after bathing or sweating 4
• Weight loss for those with obesity to reduce skin fold depth and contact 3

Treatment Approaches

• For uncomplicated intertrigo:

  • Keep the area clean and dry
  • Apply barrier preparations (zinc oxide, petrolatum) 2
  • Low-potency topical steroids may help reduce inflammation 1

• For candidal intertrigo:

  • Topical antifungals: nystatin, clotrimazole, ketoconazole, oxiconazole, or econazole 1
  • For resistant cases: oral fluconazole 3

• For bacterial superinfections:

  • Streptococcal infections: topical mupirocin or oral penicillin 1
  • Corynebacterium infections: oral erythromycin 1

Special Considerations

• Intertrigo is particularly problematic in patients with diabetes due to increased susceptibility to infections and impaired healing 3
• Recurrent cases may require investigation of underlying predisposing conditions such as diabetes, immunosuppression, or intestinal candidal colonization 3
• Establishment of proper skin care protocols and regular skin fold assessment can significantly improve outcomes 4

Differential Diagnosis

Other conditions that may present in intertriginous areas include:

• Inverse psoriasis
• Seborrheic dermatitis
• Contact dermatitis
• Erythrasma
• Tinea infections 5

Remember that proper identification and management of intertrigo under the pannus is essential to prevent complications and improve patient comfort and quality of life.