“Your diagnosis is, red lumps.” That’s just not a medical pronouncement that is going to impress anyone. So medical terminology has supplied the much more striking term, erythema nodosum, which means, you guessed it, red lumps. But all the jargon aside, erythema nodosum is indeed a very specific, though incompletely understood, entity. It’s not exceedingly common (about 1 case in 5000 people per year) although we happened to see it a couple of times in our practice in the last month or so.
Not surprisingly, it consists of red lumps which are painful and usually located along the shins. Women are affected four times more frequently than men, and although any age can get it, the peak ages are between 18 and 34 years old. It is thought to be a type of allergic or hypersensitivity reaction to some trigger. The trigger may be a strep or other infection, certain drugs, or systemic conditions such as sarcoidosis, ulcerative colitis, or even pregnancy. In many cases no obvious trigger is found.
Erythema nodosum usually begins with non-specific flu-like symptoms of fever, joint aches and fatigue. A painful skin outbreak then begins within a few days. These are tender reddish lumps that are 1-2 inches across and can look like the person whacked their shins into something repeatedly. The entire illness can last anywhere from 6 weeks to 6 months depending on the trigger. Rarely it can become chronic or recur.
The diagnosis is mostly a clinical one, based on recognizing the typical course and appearance of this disease. There is no specific blood test or x-ray for erythema nodosum. Even a biopsy of one of the lumps often does not yield a specific answer from pathology. Instead most of the medical work up is aimed at trying to determine the trigger for the outbreak. Strep tests, TB tests, chest x-rays for sarcoidosis, questioning about other symptoms, and a close look at a person’s medication list are where attention is focused.
So, what about treatment? In most patients, erythema nodosum clears on its own, though slowly. So the goal of treatment is mostly to give symptom relief by using anti-inflammatory drugs (such as ibuprofen or naproxen), cool wet compresses, elevation of the legs, and partial bed rest. Limiting activity during the initial painful stage does seem to speed recovery. In more severe cases, corticosteroids such as prednisone may be used. Beyond that, treating or removing the trigger, if possible, is helpful.
Given the odds, you’ll probably never get erythema nodosum. But if one day you develop red lumps that look (and often feel) like someone took a bat to your shins, get them checked out to be sure that’s what you have and to see what might have triggered them. We can then impress you with the pronouncement that you have, “red lumps”.