Bullous erythema ab igne: review of 19 cases finds heat removal is the mainstay of care

Erythema ab igne, sometimes known by the older name toasted skin syndrome, is a localized cutaneous condition consisting of reticular hyperpigmentation that develops after repeated, prolonged exposure to heat sources. Its bullous variant, in which blisters appear, is rarely reported, and no evidence-based treatment guideline currently exists for it.

Researchers from the Archives of Dermatological Research published review set out to characterize how bullous erythema ab igne presents clinically, which comorbidities are associated with it, and how it has been treated. The team searched PubMed and Google Scholar using the keywords bullous, erythema ab igne and toasted skin syndrome. From that search they analyzed 13 case reports and case series, and added one patient from their own institution, giving a total of 19 patients included in the review.

The demographic and anatomical pattern that emerged was fairly consistent. A slight majority of the cases, 52.6 percent, were men. The legs were involved in 89.5 percent of patients, the trunk in 10.5 percent, and the arms in 5.3 percent, reflecting the body areas most often held close to heat sources for long periods.

Heat exposure was documented in the great majority of cases. Seventeen of the 19 patients, or 89.5 percent, had been exposed to a heat source, which is consistent with the established mechanism of erythema ab igne as a heat-induced dermatosis. The review did not identify the specific heat sources for each patient in the abstracted data, but the strong association with heat exposure underscores the condition’s dependence on external thermal contact.

Comorbidities featured prominently in the collected cases. Seven patients, 36.8 percent, had diabetes, and three patients, 15.8 percent, had hypothyroidism. The authors suggest that work-up for these systemic diseases should be considered in patients presenting with bullous erythema ab igne.

Diagnostic practice varied across the reported cases. Seven cases, 36.8 percent, were diagnosed clinically without tissue sampling, while 12 cases, 63.2 percent, were confirmed by biopsy. This split illustrates that clinicians have not uniformly relied on histopathology when the clinical picture is characteristic, although most reported cases did undergo biopsy.

Treatment findings were dominated by one intervention. The most common treatment was removal of the heat source, used in 89.5 percent of cases, followed by topical antibiotics in 26.3 percent and topical steroids in 15.8 percent. Notably, most patients used a combination of treatments rather than a single approach, and the absence of an evidence-based guideline means current practice is drawn from individual case reports rather than comparative trials.

The review’s conclusions carry important caveats that the authors state explicitly. The number of reported cases of bullous erythema ab igne is small, non-English case reports were excluded from the search, data extraction was performed by a single reviewer, and no formal risk-of-bias assessment was carried out. With only 19 patients in total, the percentages reported should be read as descriptive summaries of the existing literature rather than precise population estimates.

For clinicians, the practical messages from the review are straightforward: suspect bullous erythema ab igne in patients with blistering reticular pigmentation on heat-exposed skin, ask about heat sources, consider screening for diabetes and thyroid disease, and, in diabetic patients, evaluate for peripheral neuropathy.

Subject of Research: Clinical characteristics, comorbidities and treatment of bullous erythema ab igne based on a review of published cases

Article Title: Bullous erythema ab igne: review of the literature

Article References: Hanna, S. P., Jung, J. Y., & McCullough, T. (2026). Bullous erythema ab igne: review of the literature. Archives of Dermatological Research, 318(1), Article 539. https://doi.org/10.1007/s00403-026-05027-2

Image Credits: AI Generated

DOI: 10.1007/s00403-026-05027-2

Keywords: erythema ab igne, bullous erythema ab igne, toasted skin syndrome, heat exposure, dermatology, case review, diabetes, hypothyroidism, peripheral neuropathy, skin pigmentation, blistering, topical treatment