Erythrasma is a superficial bacterial skin infection caused by Corynebacterium minutissimum. It primarily affects warm, moist areas of the body, such as the groin, underarms, and between the toes. Often mistaken for fungal infections like tinea cruris (jock itch) or intertrigo, erythrasma is distinct due to its unique fluorescence under Wood’s lamp examination.
Causes and Risk Factors
What Causes Erythrasma?
Erythrasma develops when Corynebacterium minutissimum, a normal skin bacterium, overgrows due to specific conditions. Key contributing factors include:
- Excessive sweating (hyperhidrosis)
- Obesity (skin folds retain moisture)
- Poor hygiene
- Diabetes mellitus (weakened immune response)
- Tight clothing (increases friction and moisture)
- Hot and humid climates
Symptoms of Erythrasma
Erythrasma presents with reddish-brown, scaly patches that may expand over time. Common symptoms include:
- Discoloration: Reddish-brown or pink patches with well-defined edges
- Mild itching or burning sensation
- Scaling or peeling skin
- Dry texture (unlike fungal infections, which may be moist or weeping)
Commonly Affected Areas:
- Groin (inguinal folds) – Often mistaken for jock itch
- Underarms (axillae) – Red to brown patches
- Between toes (interdigital spaces) – Resembles athlete’s foot
- Under breasts – Common in overweight individuals
Diagnosis: How Erythrasma is Identified
A clinical examination is usually sufficient, but additional diagnostic tests can confirm the condition:
- Wood’s Lamp Test: Affected skin fluoresces a coral-red color under ultraviolet light due to porphyrins produced by the bacteria.
- Skin Scraping and Microscopy: Rules out fungal infections by negative KOH test.
- Bacterial Culture: Rarely required but can confirm Corynebacterium minutissimum presence.
Treatment Options for Erythrasma
Topical Treatments
- Clindamycin or Erythromycin (1% gel/lotion) – Applied twice daily
- Fusidic Acid – Effective antibacterial cream
- Benzoyl Peroxide Wash (5-10%) – Reduces bacterial load
- Miconazole or Tolnaftate (antifungals) – Useful for mixed infections
Oral Antibiotics (Severe Cases)
- Erythromycin (250 mg, 4x daily for 7-10 days)
- Clarithromycin or Azithromycin (Shorter course, effective)
- Tetracycline or Doxycycline (Used for recurrent infections)
Home Remedies and Lifestyle Adjustments
- Good Hygiene: Regular washing with antibacterial soap
- Loose Clothing: Prevents friction and moisture buildup
- Talcum Powder: Keeps affected areas dry
- Weight Management: Reduces skin folds where bacteria thrive
Prevention: How to Avoid Recurrence
- Maintain Dry Skin: Use absorbent powders in skin folds
- Wear Breathable Fabrics: Cotton and moisture-wicking materials
- Proper Foot Care: Dry feet thoroughly after washing
- Control Blood Sugar: Essential for diabetics to reduce risk
