People with the skin condition atopic dermatitis, often known generally as eczema, may be at a greater risk of getting skin cancer, according to new research presented in the British Journal of Dermatology.
Atopic dermatitis is skin inflammation that arises from an allergic reaction. Symptoms include dryness and recurring skin rashes that are characterized by itching, redness, skin edema (swelling), and scaly, crusted skin, primarily on the hands, elbows, and back of the knees. It affects about 20% of children in the US, according to the National Institutes of Health.
Dr. Alejandro Arana, a researcher with Risk Management Resources in New Jersey, analyzed the medical records of about 4.5 million people in the UK and followed their medical history for an average of about 7 years. About 1.5% of those individuals had atopic dermatitis and 3% were diagnosed with skin cancer during the study period.
When the researchers controlled for an age-related increased risk of cancer, they found that those with atopic dermatitis had an increased rate of cancer – specifically lymphoma, melanoma, and non-melanoma skin cancers.
The researchers are not clear on the cause of the association. One theory suspects that, because eczema is an allergic, inherited disease, the immune system may have an impact. The study did not focus on eczema treatments, but some medications for atopic dermatitis have been linked to an increased risk of certain cancers.
The results of the study do not prove that having atopic dermatitis causes cancer, the investigators emphasize. Even among patients with eczema, the overall cancer risk was still low. “Each study should be seen as a brick in the wall of knowledge,” said Dr. Arana.