Allergy and Dermatology Best Practices for Collaborative Diagnosis and Care

Allergists and immunologists are key collaborators for dermatologists. Conditions such as urticaria and angioedema are well-suited for an allergist’s expertise. Providing dermatology referrals for patients with suspected malignancies helps put those patients in front the correct physician promptly.

In a session at the American College of Asthma, Allergy & Immunology (ACAAI)’s 2021 Annual Scientific Meeting, held November 4 to 8 in New Orleans, Louisiana,¹ David R. Weldon, MD, FACAAI, FAAAI, an associate professor of Internal Medicine at Texas A&M University Health Science Center, School of Medicine in Bryan-College Station, Texas, demonstrated punch biopsies for allergists and discussed both the scope and limitations for allergists as dermatological collaborators and diagnosticians.

Punch biopsies are a staple tool in any dermatology practice. Allergists, Weldon said, likely learned how to perform the procedure in medical school but are unlikely to perform it frequently in their practices. Hands-on practice gives this group the skill to collaborate more efficiently with dermatologists to define skin conditions commonly seen in both specialty’s practices and provide tools to either diagnose or refer as appropriate. 

Weldon told Dermatology Times® that both specialties need to consider an individual patient’s treatment course, not just their condition, before considering when to treat, when to refer, and when to collaborate. “Even with 4 dermatologists in our region, they are still very busy and are willing to send patients with urticaria and angioedema to me,” he said.

Even with typically allergic conditions, however, dermatologists should not be surprised to see some patients referred back to their practice for long-term management if they receive an unexpected diagnosis. “If I have a patient who has an initial urticarial presentation of bullous pemphigoid (BP) and the evaluation reveals BP, then that patient is immediately referred to our dermatologist for management,” Weldon said. “I may help out the patient with temporizing therapy, but the actual management is relegated to the dermatologist.”

For certain conditions, both allergists and dermatologists need to closely inspect a patient to determine the best specialist for their case. For example, in patients with atopic dermatitis (AD), dermatologists refer patients who require biologics for the management of moderate to severe disease to Weldon, but if he has a patient who is a good candidate for UVB therapy for the same condition, he refers to a dermatologist. “There seem to be new developments that arise between specialties almost every year and the collaboration between allergists and dermatologists has been very educational and exciting to see the newest advances in manipulating immune pathways to treat our patients’ rashes,” Weldon said.

Investigative biologics ligelizumab (QGE031; Novartis International AG) for chronic spontaneous urticaria and nemolizumab (Galderma) for pruritis are 2 treatments Weldon is most looking forward to adding to his armamentarium. He is also interested in new products that address nonhistaminergic causes of pruritis. 

While the rise of biologics has widened the overlap between the 2 specialties, he reiterated that allergists are not dermatologists and there are some cases in which referral is the first—and only—option. “The purpose of the workshop is not to address anything that might be suspicious for cancer—whether that be melanoma, basal cell or squamous cell [carcinomas]…an allergist should not be trying to manage skin cancers, in my opinion,” Weldon said.

“One of the reasons why the FDA issued a black box warning for calcineurin inhibitors for the management of [AD] was the number of reported cases of skin cancer that were erroneously misdiagnosed by the provider as eczema [and failed to respond with the calcineurin inhibitor],” he added. In addition, he said, allergists are not trained in shave biopsies, which could result in misdiagnosis of a malignancy if performed incorrectly.

Mycosis fungoides is Weldon’s 1 exception to the rule. “Having an allergist entertain this condition as a possibility [early] may improve the patient’s outcome when the appropriate therapy is pursued by a dermatologist or dermatologist at a major medical center,” he said. 

Collaboration with pathologists and dermatopathologists can help clarify what technology exists determining clonal relationships for T-cells in defining mycosis fungoides.

Weldon noted that patients may often come into allergy and immunology practices with rashes they have been unable to get a diagnosis for. The ability to biopsy lets them walk out knowing that an important step in the diagnostic process has been accomplished. 

Disclosure:

Weldon reported no relevant disclosures.

Reference:

1. Weldon DR. Hands-on workshop: punching through dermatitis dilemmas: biopsy overview. Presented at: ACAAI 2021 Annual Scientific Meeting; November 4-8, 2021; in New Orleans, LA, and virtual.