Jason Hawkes, MD: Strategies for Diagnosing Acute, Chronic Spontaneous Urticaria

In a talk titled ‘Acute & Chronic Spontaneous Urticaria: Diagnostic and Therapeutic Strategies,’ presented at the Maui Derm NP+PA Fall 2024 conference, attendees were given a series of challenging cases in urticaria designed to test their making of the correct diagnosis.

The talk was presented by Jason Ezra Hawkes, MD, a dermatologist and investigator at the Oregon Medical Research Center in Portland.

“I want you to think of urticaria in the same way that we think about alopecia,” Hawkes said. “It doesn't mean much by itself. So there’s alopecia, there’s scarring alopecia, there's non-scar alopecia. I want you to think of urticaria the same way. There's different types of urticaria. This is a heterogeneous group. This is a bucket that's going to capture all types of urticaria.”

He noted that urticaria typically has a 2 to 1 female predominance.

“Urticaria as a bucket is characterized by either wheals or angiodema,” Hawkes explained. “This is a superficial swelling in the skin…These, by definition, last less than 24 hours. If there’s 1 clinical pearl about how to tease out urticaria, this is it. Almost no other skin diseases that we see have transient wheals that last less than 24 hours.”

Hawkes added that if a clinician, physician assistant, or other provider is not sure if a patient has urticaria, 99 times out of 100 this observation will lead to such a conclusion.

“Angioedema is a little different from the wheals,” Hawkes said. “This involves deeper swelling…Notice the time frame, which is less than 72 hours. That means this type of swelling in the skin takes longer to resolve. So if you have a patient come in with a swollen lip or swollen eye, this can take longer to resolve but they can still have urticaria.”

Hawkes later noted that wheals are not a primary skin lesion, which he added is critical given the heterogeneity of wheals. He notes that providers should ask patients how long an individual wheal has lasted, as opposed to how long they have been experiencing them in general.

“What do you think drives people to the ER, urgent care, or the hospital?” he asked. “It's angiodema, not the hives as much. This is the scary part and it lasts for days…So remember, we're talking about urticaria and you can make a diagnosis of urticaria just based on angioedema.”

However, Hawkes noted that there is a caveat to reaching such a conclusion.

“We've talked a lot about T-cell disorders like eczema, psoriasis, vitiligo, even HS, and we've talked about B-cell disorders, autoimmune conditions, and lupus, for example,” Hawkes said. “We're now talking about mast cells, where the mas cell is the predominant immune cell found in the skin of these patients. We're not going to talk about the same mechanisms that we have with eczema or atopic dermatitis or psoriasis, for example, because we're not necessarily talking about the same player.”

He explained that mast cells are another immune cell that comes from the same bone marrow cells but have a different function.

“These cells get activated and then they degranulate,” Hawkes said. “They release the granules. All those proteins are going to contribute to the pathophysiology of this condition. All types of urticaria, and it doesn't matter if they're acute, inducible, or chronic spontaneous: mast cell degranulation is going to be the key feature, not T-cells as a predominant cell.”

For additional information on presentations such as these, view our coverage of the Maui Derm NP+PA Fall 2024 conference in Nashville.

The quotes included in this summary were edited for the purposes of clarity. Hawkes has served as an advisor or consultant for Apogee, Arcutis, Bl, Blueprint Medicines, BMS, Boxer Capital LLC, Cogent Biosciences, Dermavant, Galderma, Institute for Systems Biology (ISB), Jansen, LEO, Novartis, Regeneron, Sanofi, Sun Pharma, Takeda, and UCB. He is also on the Medical Board of the National Psoriasis Foundation (NPF).