Prurigo nodularis (PN) is a bothersome skin condition characterized by raised, intensely itchy, often painful bumps on the arms, legs, and trunk.
This condition can occur in anyone, but is most common in middle-aged adults. Prurigo nodularis greatly affects a person’s quality of life, including sleep disturbances and higher rates of anxiety and depression. Patients with severe PN have an increased amount of inflammation in their blood, and PN is commonly associated with other medical conditions.
Prurigo nodularis appears as thick, scaly, raised bumps on the skin that are very itchy and can be painful. Severe itch is characteristic of PN and leads to scratching, bleeding, and thickening of the nodules. The bumps can be anywhere on the body but are always within reach, with the arms and legs the most common areas. Black patients with PN often have firmer, larger, and darker bumps that tend to leave dark spots that can take many months to years to fade. Once the itch starts to improve with treatment, the raised bumps gradually heal, frequently with scarring.
A dermatologist can usually diagnose PN on clinical examination. Sometimes, a dermatologist will perform a skin biopsy to rule out other diagnoses. Prurigo nodularis is more common in patients with other medical conditions, including diabetes, liver, kidney, and thyroid problems, and certain infections. Physicians will often screen patients with PN for these medical issues.
There is no cure for PN. The main treatment goal is decreasing itch because the bumps fade once the itch improves. The most common initial treatment for mild PN is topical steroid creams or ointments or local corticosteroid injections into the bumps to reduce inflammation. Light therapy, a treatment with a special medical-grade light machine in the physician’s office, is another treatment option. Because PN is usually widespread, most patients will need treatment with oral medications or injections to help improve itching. Some medications, such as gabapentin, are used to target the nerves that transmit itch from the skin to the brain. Patients with severe PN are often prescribed medications that lower the immune system (immunosuppressants) to decrease inflammation.
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Published Online: February 9, 2022. doi:10.1001/jamadermatol.2021.5307
Conflict of Interest Disclosures: Dr Kwatra reported personal fees from AbbVie, Celldex, Galderma, Incyte, Johnson & Johnson, Novartis, Regeneron, Sanofi, and Kiniksa and grants from Pfizer outside the submitted work.