Vesicular Circular Rash in an Athlete
Most Likely Diagnosis
The most likely diagnosis is tinea corporis (ringworm), which presents as circular scaly lesions with central clearing, though the vesicular component raises consideration for herpes gladiatorum (HSV) or tinea pedis with vesiculopustular features. 1, 2
Diagnostic Approach
Key Clinical Features to Distinguish
Tinea corporis characteristics:
- Circular, scaly lesions with central clearing and raised borders 2
- May have vesiculopustular features at the active edge 2
- Common in contact sports, especially wrestling 1, 3
- Trichophyton tonsurans causes >80-90% of cases in wrestlers 1, 3
Herpes gladiatorum characteristics:
- Vesicular or ulcerative lesions in clusters 4
- Often on exposed areas (face, neck, arms) 4
- Painful, may have prodromal symptoms 4
- Common in wrestlers and rugby players 4
Tinea pedis with vesicular features:
Confirm Diagnosis
For suspected tinea corporis:
- KOH preparation showing hyphae/arthroconidia provides immediate confirmation 1, 5
- Fungal culture on Sabouraud agar is the gold standard 5
For suspected herpes gladiatorum:
- PCR of vesicular lesion scrapings in complex cases 4
- Direct fluorescent antibody staining or enzyme immunoassay 4
Treatment Algorithm
If Tinea Corporis is Confirmed
For localized disease (solitary or closely clustered lesions that can be covered):
- Topical terbinafine 1% cream applied twice daily for 1 week is first-line 1, 6
- Alternative: Naftifine (also preferred for wrestlers) 1
- Less preferred: Clotrimazole 1% twice daily for 2-4 weeks 2
For extensive disease (multiple widespread lesions that cannot be adequately covered):
- Terbinafine 250 mg daily for 1-2 weeks is superior for T. tonsurans infections 1, 2, 5
- Alternative: Itraconazole 100 mg daily for 15 days (87% mycological cure rate vs. griseofulvin's 57%) 1, 2, 5
If Herpes Gladiatorum is Confirmed
Valacyclovir 500 mg once or twice daily for 7 days when given within 24 hours of symptom onset shortens HSV PCR clearance time by 21% 4
- Advise good hydration to minimize nephrotoxicity risk 4
Return to Competition Criteria
For tinea corporis:
- Minimum 72 hours of topical or systemic antifungal therapy required before return 1
- Lesions must be covered with gas-permeable dressing 1
- Athlete must not have extensive or active disease that cannot be adequately covered 1
- Disqualification if extensive active lesions confirmed by KOH prep 1, 5
For herpes gladiatorum:
- 3 to 8 days of isolation with suspension of competition 4
- Exclude until all lesions are fully crusted or physician provides written statement that condition is noninfectious 4
Prevention Strategies
For tinea corporis outbreaks:
- Avoid skin-to-skin contact with infected individuals 1, 2
- Do not share towels, clothing, or personal items 1, 2
- Screen and treat sparring partners even if asymptomatic (>50% of household contacts may be affected) 1
- Daily change of clothing and careful drying after showers 1
For herpes gladiatorum outbreaks:
- Pre-competition examination for vesicular or ulcerative lesions on exposed areas 4
- Clean wrestling mats with freshly prepared bleach solution (1/4 cup bleach in 1 gallon water) for minimum 15 seconds contact time daily 4
- Consider suppressive valacyclovir therapy for athletes with history of recurrent herpes 4
Critical Pitfalls to Avoid
Do not allow return to competition before 72 hours of treatment for tinea corporis, even if lesions appear improved clinically 1
Do not rely solely on clinical response—mycological cure (negative microscopy and culture) is the definitive treatment endpoint 1, 2
Do not fail to screen and treat sparring partners and household contacts, as this leads to reinfection and further outbreaks 1
Do not use trimethoprim-sulfamethoxazole as single agent if bacterial superinfection is suspected, due to intrinsic resistance of group A Streptococcus 4