What is the cause and treatment of a rash on my arms and knees after starting wrestling?

Rash on Arms and Knees After Starting Wrestling

This is most likely herpes gladiatorum (mat herpes) or impetigo—both highly contagious skin infections common in wrestlers from skin-to-skin contact and shared equipment. 1

Immediate Clinical Assessment

Examine the rash morphology carefully:

• Vesicular/clustered blisters = Herpes gladiatorum (HSV-1) until proven otherwise 1
• Honey-crusted lesions or pustules = Impetigo (Staphylococcus/Streptococcus) 1
• Red, scaly patches with central clearing = Tinea corporis (ringworm) 1

Key Diagnostic Features to Look For

History elements that matter:

• Exact timing: Did rash appear within 2-8 days of starting wrestling? (typical for herpes gladiatorum) 1
• Symptoms: Burning/tingling before blisters suggests HSV; pruritus suggests fungal 1
• Teammates affected: Outbreaks are common in contact sports 1
• Distribution: Herpes gladiatorum classically affects head/neck/arms; impetigo can be anywhere with skin trauma 1

Most Likely Diagnoses in Wrestling Context

Herpes Gladiatorum (Most Serious)

• Grouped vesicles on erythematous base, often painful 1
• May have prodrome of tingling/burning 1
• Requires immediate exclusion from wrestling until lesions completely crusted 1
• Viral culture or PCR if available for confirmation 1

Impetigo (Most Common)

• Honey-colored crusted erosions or pustules 1
• Often at sites of minor trauma (knees, elbows) 1
• Bacterial culture if not responding to empiric treatment 1

Tinea Corporis (Ringworm)

• Annular scaly plaques with raised borders 1
• KOH preparation shows hyphae 1

Treatment Algorithm

For vesicular/suspected herpes gladiatorum:

• Start oral acyclovir 400mg 5x daily or valacyclovir 1g twice daily immediately 1
• Exclude from all contact sports until lesions fully crusted 1
• Consider suppressive therapy if recurrent 1

For honey-crusted/suspected impetigo:

• Topical mupirocin 2% three times daily for localized lesions 1
• Oral antibiotics (cephalexin 500mg four times daily or dicloxacillin) if extensive 1
• Exclude from wrestling until 24 hours after starting antibiotics 1

For scaly annular lesions/suspected tinea:

• Topical antifungal (clotrimazole, terbinafine) twice daily 1
• Can continue wrestling if covered 1

For any inflammatory component:

• Low-potency topical corticosteroid (hydrocortisone 2.5%) can be applied to reduce inflammation, but never on active infection 2, 3
• Apply twice daily to non-infected inflamed areas only 2

Critical Pitfalls to Avoid

• Do not delay treatment waiting for culture results if herpes gladiatorum suspected—this is highly contagious and can cause outbreaks 1
• Do not allow return to wrestling prematurely—this violates most athletic association rules and spreads infection 1
• Do not use topical steroids on suspected infection—this can worsen bacterial/viral/fungal infections 1, 2
• Do not assume it's just "mat burn"—infectious causes require specific treatment 1

When to Refer

• Extensive involvement (>10% body surface area) 1
• Failure to respond to appropriate therapy within 48-72 hours 1
• Recurrent episodes suggesting need for suppressive therapy 1
• Diagnostic uncertainty between infectious causes 1

Prevention for Future

• Shower immediately after wrestling practice 1
• Avoid sharing towels, razors, or equipment 1
• Ensure mats are cleaned with appropriate disinfectant between uses 1
• Report any skin lesions to coach immediately 1