This month’s news from across the specialty
What’s hot
June 1, 2025
In this monthly column, members of the DermWorld Editorial Advisory Workgroup identify exciting news from across the specialty.
The balancing of the efficacy against the toxicities of immunotherapy for melanoma remains a vigorous point of debate within multidisciplinary tumor boards. Treating early melanoma with immunotherapy will introduce a greater risk of death from drug than from disease. Treating late-staged melanoma in the setting of brain metastases with immunotherapy risks brain swelling and earlier death. Fager et al recently reported a retrospective study of their experience with advanced melanoma defined as unresectable stages III and IV treated at a single institution in Sweden between 2013 and 2019 (BJC Rep. 2025 Apr 11;3(1):22). They found potential pearls informing the question of when to give immunotherapy to patients with advanced melanoma.
395 patients were divided into 91 patients who developed melanoma brain metastases and 304 patients without brain involvement. Treatment with immunotherapy as a first-line treatment was associated with decreased progression to brain metastases. Interestingly, none of the 11 patients receiving the first-line treatment of CTLA-4 immunotherapy — monotherapy or combination with PD-1 inhibition — developed brain metastases. This finding is curious, because other studies have demonstrated that PD-1 inhibition has a superior cure rate relative to CTLA-4 when started after diagnosis of brain metastases.
An additional insight from their cohort is the association of elevated plasma S100B as a predictor of progression to brain metastases. Future research is needed to determine if S100B will strengthen the surveillance of other circulating markers such as LDH and tumor DNA.
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Each year is shaped by a few challenging clinical cases, and one of mine involved a patient with hidradenitis suppurativa (HS) who failed all treatments until a retrial of infliximab at higher dosing led to marked improvement. This made us question whether patient compliance had contributed to previous treatment failures — a mystery yet to be fully explored.
At the recent AAD Annual Meeting, I attended a lecture by Dr. Alexandra Charrow, director of the Hidradenitis Suppurativa Clinic at Brigham and Women’s Hospital, on HS therapeutics. She discussed why biologics fail in treating HS, emphasizing therapeutic drug monitoring (TDM) to prevent premature discontinuation. Currently, there are only three FDA-approved treatments for HS, which reduce lesions by 50-70% in about half of patients. Biologic failures can result from rapid clearance and/or antibody formation. Anti-drug antibody testing is available for adalimumab, infliximab, golimumab, and ustekinumab, but not for IL-17 inhibitors, which thankfully have low rates of antibody formation.
In TDM, monitoring trough drug levels before the next dose is crucial (doi: 10.1007/s40257-020-00575-3). More research is needed to determine optimal trough drug levels for HS. If anti-TNF trough levels are low without antibodies, the dose can be increased. If antibodies are present, switching medications is necessary. For patients switching to another TNF inhibitor, methotrexate or azathioprine can help prevent antibody formation. For patients with high anti-TNF levels, switching to anti-IL-17 therapy or adding it to the regimen are options.
Supplements have gone Hollywood with social media influencers and late-night infomercials alike promising to improve everything from hair, skin, and nails to memory and weight with regimens of over-the-counter pills. One popular category that has emerged and endured is that of probiotics. As we learn more about the gut/brain/skin connections, it has been suggested that maternal supplementation with probiotics may reduce the risk of atopic dermatitis in their infants. In a 2012 study in the Journal of Allergy and Clinical Immunology, atopic mothers were randomized to receive probiotics or placebo, and at 24 months, found a significant reduction in diagnosis of atopic dermatitis in the probiotic group with no adverse events noted. Studies since then have found variable benefits but confirm low risk. With many companies now marketing probiotics directly to expectant mothers, dermatologists should counsel their patients accordingly, keeping in mind that regulation of these products is limited.
More What’s Hot!
Check out more What’s Hot columns from the DermWorld Editorial Advisory Workgroup.
It is that time of year for those enthusiastic about contact dermatitis. The American Contact Dermatitis Society recently announced that the 2025 Allergen of the Year honor goes to toluene-2,5-diamine sulfate (PTDS). PTDS is a chemical frequently used in permanent hair dyes and bleach-toner formulations. PTDS is also used in color photography development and textile and fur dyes.
PTDS is not found in standard allergen screens and as a result it is often underdiagnosed and underreported as a contact allergen. PTDS can be a hair dye alternative to those who are paraphenylenediamine (PPD) allergic but can also be a hair dye allergen. Cross-reactivity can be seen between PTDS and PPD, therefore, patch testing to PTDS should be conducted before using it as a dye in those who are found to be PPD allergic.
The clinical relevance of PTDS is often high with several reports noting relevance over 70%. It can present as an occupational contact dermatitis in hairdressers applying the dye and in those getting their hair dyed.
With studies reporting that 50-80% of women in the United States, European Union, and Japan have used hair dyes, it is important for clinicians to be aware of the allergens that can be found in hair dyes and what alternatives may be available.
Highlighting PTDS as the 2025 Allergen of the Year brings attention to PTDS as both a potential PPD alternative and a potential allergen. It is not routinely patch tested leading to underdiagnosis and should be considered in patch test series.
