Findings from a recent study suggest an updated categorization system for blistering skin conditions in pediatric patients more accurately represents how these conditions present in young patients and supports both research and more effective care.
In the paper, published in the Journal of the American Academy of Dermatology (March 2024; 90(3):635-637), researchers retrospectively collected data on North American pediatric patients who had blistering skin reactions and reclassified them with a set of new pediatric-specific definitions. One of their goals was to gain insight into the best treatment choices based on the clinical picture and cause.
“One of the things that was emphasized by the results of our study is that those patients who had what we would now include in that category of RIME were given very heterogeneous diagnoses before and that would have impaired our ability to study them as a whole to look at outcomes and to look at best treatment,” said the study’s senior author Dr. Michele Ramien during a presentation at the Great Lakes Immuno-Dermatology Exchange (GLIDE) 5.0 meeting in Oct. 2023.
Dr. Ramien is the President of the Canadian Dermatology Association and is a Clinician-Investigator at the Alberta Children’s Hospital in Calgary, Alberta. Her practice is focused on clinical care of medically or dermatologically complex children.
When the standard categorization system for blistering skin diseases was developed, no pediatric cases were included, Dr. Ramien noted. She said this is important as body surface areas involved develop and are distributed differently in children, with much more head and neck involvement, which may play a role in prognosis for children.
“Then we have these cases, predominantly in pediatrics and young adults, where they have a lot of mucous membrane involvement, but not much skin involvement. If we look back to the traditional classification system, there is no category for patients that don't have skin involvement.”
To address the challenges of classifying pediatric cases of blistering skin diseases, a group of pediatric and adult dermatologists developed new criteria for sorting pediatric cases, Dr. Ramien said.
“Erythema multiforme was more or less left alone as the erythema multiforme minor entity. Drug-induced cases were collapsed into a single category of Drug-Induced Epidermal Necrolysis because we know those patients, even if they present with a low body surface area involvement, can sometimes evolve to have more skin involvement and mucous membrane involvement over time,” Dr. Ramien said.
This change in categorizing drug-induced cases created space for a new category known as Reactive Infectious Mucocutaneous Eruption or RIME. Under this new category mycoplasma-induced rash and mucositis (MIRM) would be identified as RIME from mycoplasma pneumonia, she said.
Another strength of this new classification system is that the pathophysiology correlates better with the cause and the diagnosis, said Dr. Ramien.
Dr. Ramien said the diagnostic criteria that have been proposed for RIME are that patients would have at least two of:
0% to 10% body surface area involvement with vesicular, bullous, or targetoid lesions
Mucositis affecting two or more sites
A non-contributory medication history
Patients “only need to have two of those three, plus some kind of evidence of a recent infection, either clinical signs, lab tests that prove infection, or an x-ray,” she said.
“One early sign that's been reported with RIME is a duck-like lip sign, where the mucosa and semi-mucosa become very edematous and swollen due to the early inflammation of the clinical process,” she said. “A metallic taste is also anecdotally reported by many patients who have had recurrent episodes.”
An expanded version of this story will be published in an upcoming issue of The Chronicle of Skin & Allergy.