Caroline Nelson, MD: Differentiating Allergic, Non-Allergic Dermatologic Conditions

In her new HCPLive interview, Caroline Nelson, MD, discussed several topics covered in her presentation, including prescribing topical treatments and distinguishing allergic and non-allergic skin reactions.

She is known for her work as the director of inpatient dermatology at the Yale School of Medicine.

Nelson’s presentation was titled ‘Dermatology for the Allergist’ and featured at the American Academy of Allergy, Asthma & Immunology (AAAAI) 2023 Annual Meeting in San Antonio, TX.

She began with a discussion of some of the more common skin conditions that many allergists will observe when treating patients.

“We could almost divide it into a few different buckets: those that are inflammatory and those that are drug-induced,” she explained. “So in terms of inflammatory, we think about urticaria—that's an important point of overlap between allergy and immunology and dermatology—as well as atopic dermatitis and contact dermatitis.”

Nelson went on to explain the other category of drug-induced skin reactions observed in patients.

“And then in terms of drug reactions, we're often called to think about patients who have morbilliform drug reactions, but also some of our more severe drug reactions, including Stevens-Johnson Syndrome, toxic epidermal necrolysis, and the drug reaction with eosinophilia and systemic symptoms,” she explained.

Nelson later discussed methods for differentiating allergic and non-allergic reactions, with specific examples to illustrate her views.

“There are often subtle clues on the skin that we use to help differentiate those that are allergic versus non-allergic,” she said. “So I might just give the example of urticaria. When we see hives, and they migrate within 24 hours, we've circled them. We know that they have migrated, that is a helpful and reassuring clue. But if the hives persist for longer than 24 to 48 hours, if it causes burning instead of itch, if it leaves behind a bruise, these sorts of things can be subtle clues to the presence of alternative diagnoses.”

Subtle clues in a patient’s systemic features that they present with may also be indicators, she explained.

“So for example, in the case of urticarial vasculitis: do they have a fever?” she said. “Do they have other joint manifestations? Do they have other things that make us think this is something beyond simple urticaria?”

For more about her AAAAI presentation, view the full HCPLive interview above.