Hiker's Rash - Exercise Induced Vasculitis

Legs of a 61 year-old woman after extensive hiking. CMAJ. 2018 FEb;190:E195

If you've pulled down your socks after a long day of hiking and found an itchy, sensitive, or painful rash on your lower legs, your first thought was probably wondering what patch of poisonous plants you brushed against. Chances are, it's not a plant that caused this problem, but your own body.

Exercise-induced vasculitis, also known as hiker's or golfer's rash, is a common disorder in women over 50 after hiking, running, golfing, or spending all day on their feet. The rash is often red or purplish and raised. It can feel completely painless, or it might itch or burn. The hallmark of this type of rash is the sparing of the skin compressed by the sock. So, you might see a clear band on the skin marking the elastic portion of the sock.

This type of rash is more common in hot and humid conditions. The thought is that the body pushes more circulation closer to the skin in hot weather to cool itself. As women age, their leg muscles may not do as good a job of assisting in the pumping action to return this blood flow to the heart. Therefore, the blood tends to pool in the leg's small vessels located under the skin and irritates them, causing the rash.

Things to consider

There's no cause for this malady other than the exercise or prolonged standing itself. However, other pathologies can cause similar reactions. As always, consult with your physician to rule out any other causes, especially if you have an accompanying fever, joint pain, abdominal pain, weight loss, or unusual fatigue. They may conduct a physical exam and laboratory tests.

Exercise-induced vasculitis is self-limiting and usually goes away on its own after a week or two. Some things that might help with the symptoms are over-the-counter drugs, such as non-steroidal anti-inflammatory drugs, topical corticosteroid cream, and oral anti-histamines, all used as directed. A cool bath followed by putting your feet up may assist with circulation and help relieve any residual swelling.

As far as prevention goes, try dressing as cooly as possible when hiking. However, keep your legs covered to avoid sunlight which may make the syndrome worse. Elevate your feet or massage your legs during breaks to relieve some of the circulation load in your legs. Compression stockings may help but aren't a proven prevention method. As always, stay well hydrated. Dehydration may make this problem worse.