What type of vasculitis flares with warm temperatures?

Exercise-Induced Vasculitis (Golfer's Vasculitis)

Exercise-induced vasculitis is the type of vasculitis that flares up with warm temperatures, occurring after prolonged physical activity in hot weather. This condition, also known as "Disney rash" or "Golfer's vasculitis," is a benign, self-limiting cutaneous small vessel vasculitis 1, 2.

Clinical Presentation

The condition presents with highly characteristic features:

• Erythematous, purpuric, or urticarial plaques on the lower legs, typically above the ankles
• Spares areas covered by compression socks or stockings - this is a key diagnostic feature 1, 2
• Associated symptoms include pruritus, burning sensation, pain, and mild edema 2
• Occurs predominantly in women over 50 years old after extended walking, hiking, or dancing in hot, humid conditions 1, 2

Pathophysiology

The mechanism involves:

• Acute failure of the calf muscle pump combined with thermoregulation decompensation during prolonged, unusual exercise in hot weather 2
• Results in venous stasis that triggers the vasculitic response
• Histopathology demonstrates leukocytoclastic vasculitis in 95% of cases, with C3 or IgM deposits 2

Important Distinguishing Features

This is NOT the same as:

• Cholinergic urticaria (which is triggered by sweating/overheating but presents differently) 3
• Urticarial vasculitis (which has persistent lesions lasting days, not the self-limited course of exercise-induced vasculitis) 3

Management Approach

Treatment is primarily supportive 1, 2:

1. Immediate measures:

   • Topical corticosteroids (e.g., mometasone cream twice daily) 1
   • Compression stockings
   • Leg elevation
   • Reduced physical activity during acute phase

2. Prevention of recurrence (relapses occur in 77.5% when triggering conditions persist) 2:

   • Wear compression hosiery during prolonged exercise
   • Avoid extended physical activity in hot weather
   • Consider manual lymphatic drainage
   • Wear light, breathable clothing 2

3. Expected course:

   • Lesions resolve spontaneously within 10-14 days 1, 2
   • No systemic investigations needed - blood work is negative 2, 4

Clinical Pitfall

This condition is frequently misdiagnosed as allergic reactions or other forms of vasculitis 4, 5. The key to diagnosis is recognizing the stereotypical presentation: lower leg rash sparing sock-covered areas after prolonged exercise in heat, in an otherwise healthy individual with negative systemic workup. Extensive allergy testing or vasculitis screening is unnecessary and should be avoided 5.