Etiology of Intertrigo
Intertrigo is primarily caused by skin-on-skin friction in opposing skin surfaces, combined with moisture and lack of ventilation, which creates an environment conducive to secondary microbial infections. 1, 2
Primary Causative Factors
Mechanical factors:
- Skin-to-skin friction (the primary mechanism)
- Maceration from trapped moisture
- Poor air circulation in skin folds
- Occlusion of skin surfaces
Environmental factors:
- Heat and humidity (exacerbate the condition)
- Sweating
- Inadequate drying after bathing
Predisposing conditions:
- Obesity (creates additional skin folds)
- Diabetes mellitus
- Immunocompromised states
- Incontinence (urine and feces act as irritants)
Secondary Microbial Infections
The damaged skin barrier in intertrigo creates an ideal environment for secondary infections, which are extremely common and include:
Fungal Infections
- Candida species (most commonly C. albicans) - identified by characteristic satellite pustules 1
- Dermatophytes - can cause tinea infections in intertriginous areas
Bacterial Infections
- Staphylococcus aureus (including MRSA)
- Group A beta-hemolytic streptococcus - causes erythema and peripheral scaling 1
- Corynebacterium minutissimum (causes erythrasma) - can be identified using Wood's lamp examination (coral-red fluorescence) 1
- Pseudomonas aeruginosa and other gram-negative bacteria
Anatomical Distribution
Intertrigo can affect any area where skin surfaces meet and rub against each other:
- Axillae
- Inframammary folds
- Pannus (abdominal fold)
- Inguinal folds
- Intergluteal cleft
- Toe and finger web spaces
- Neck folds (especially in infants)
Pathophysiological Mechanism
- Initial skin-on-skin friction causes irritation and mild inflammation
- Moisture accumulation from sweat, urine, or other bodily secretions exacerbates the condition
- The warm, moist environment promotes maceration of the stratum corneum
- Skin barrier function becomes compromised
- Secondary colonization by microorganisms occurs
- Inflammatory response intensifies, creating a cycle of worsening irritation
Risk Factors
- Obesity (BMI >30)
- Diabetes mellitus (especially with poor glycemic control)
- Hyperhidrosis (excessive sweating)
- Immunosuppression
- Hot, humid climate
- Poor hygiene practices
- Tight-fitting clothing
- Incontinence
- Limited mobility
- Use of occlusive topical products
Understanding the multifactorial etiology of intertrigo is crucial for effective management, as addressing only the secondary infections without correcting the primary mechanical and environmental factors will lead to recurrence 3.