Is This Atopic Dermatitis or Ringworm?
My husband, who also suffers from atopic dermatitis, had some lesions on his legs that weren't responding to his usual prescription ointment. They were red and round and itchy, pretty similar to his usual breakouts except that they were smaller and not getting better with his treatment. He didn't think much about it until he went in for an unrelated sinus problem. His GP took one look and said, "That's ringworm!"
Is ringworm really a worm?
Ringworm is a colloquial term for a dermatophyte -- a fungus that grows in the skin. It's not really a worm. The name comes from the way it appears, in an enlarging circle of red scabs. Before modern medicine, people thought it was a worm under the skin. But it's related to mushrooms, yeast, athletes' foot; all of these are fungi.
Not all cases have a typical ring appearance. Sometimes it can be a large plaque of affected skin. The scalp can be affected, and might look more like red bumps and scabs.
Do you have a cat?
Most physicians will ask a person diagnosed with ringworm if they have a cat. That is because some species of ringworm have a strong affinity for felines. Although it is possible to be infected from contact with an infected cat, these dermatophytes can live in the soil. You are more likely to get exposed by gardening than from a cat. And many other species can also get ringworm. You can also get it from another person or from contaminated objects, like towels.
Cats and ringworm
Most cats with ringworm are symptomatic. They will have patchy hair loss, especially on the face and feet, and might have small scabs on their skin. Interestingly, they don't get the ring pattern commonly seen on humans. If you are concerned that your cat (or dog, or guinea pig) is the culprit, make an appointment with your veterinarian. They can do a quick test with a special light, which will make most feline dermatophytes fluoresce (or glow) under the light. However, not 100% of feline dermatophytes glow, so a fungal culture may be required to definitively determine if your pet is a carrier of ringworm.
How do you prevent ringworm?
Ringworm is opportunistic. If you have atopic dermatitis, you might have small breaks in your skin. This breach of your immune system's first line of defense - a barrier - can let the fungus in. Try to keep your skin healthy and intact to prevent secondary infections. Also, don't share towels, sports or gym equipment, and wear flip-flops in public showers. It's always a good idea to wash your hands after handling animals.
How is ringworm treated?
In my husband's case, he got a new prescription with a steroid and an antifungal in it. Once he put this cream on the spots regularly, they cleared up, too. Fungal infections can be tenacious and usually require a long treatment period. Make sure you use prescribed antifungal treatment for the entire recommended course.
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