Sir,

A 21-year-old woman with an unremarkable medical history, 1.72 m, 87 kg, consulted for lesions that appeared a week prior to consultation. Clinical examination revealed symmetrical, reticulated, pigmented rash below both breasts (Figs. 1a and 1b). The clinical diagnosis was compatible with erythema ab igne. No additional laboratory examinations were conducted as the etiology of the rash was evident, and the clinical condition of the patient was excellent. The patient, while the external temperature exceeded 40°C, had been working on two computers simultaneously, therefore, excessive heat is considered to be linked with the development of erythema ab igne.

Figure 1: a) Erythema ab igne on and below both breasts. b) Erythema ab igne on and below the left breast.

This dermatological condition manifests with the appearance of reticulated pigmented rash in parts of the body following exposure to excessive heat [1,2]. Predilection sites include the back, where heaters are usually applied, the abdomen, the inner surface of thighs, and the upper arms and lower legs. Breasts are an unusual site. Erythema ab igne has been reported in patients using laptops in contact with the affected areas [3]. Although affection is benign, associations with autoimmunity as well as malignant transformation to squamous cell carcinoma have been described in the literature [4,5].

While not mentioned, a thorough review of the literature revealed that most patients presenting with erythema ab igne are females. This might be explained by hormonal changes that provoke alterations in thermoregulation in females. Obesity observed in the reported patient, 1.72 m, 87 kg, might have contributed to the development of erythema ab igne, as excess fat leads to diminished heat elimination. Another publication reported three cases of erythema igne occurring in three girls with anorexia nervosa [6]. It is known that anorexia nervosa is associated with weight loss, intolerance to cold vasoconstriction, and increased need for heat. The assumption that both an excess in body weight or emaciation may be associated with the development of erythema ab igne should be taken into account. This case is reported because of the unusual location of erythema ab igne (no case on and below the breasts was found in the literature) and to increase awareness of physicians about the possible associations of the affection with either excessive or diminished body weight, especially in female patients.

REFERENCES

1.  Kettelhut EA, Traylor J, Sathe NC, Roach JP. Erythema ab igne. 2022 Dec 24. In:StatPearls [Internet]. Treasure Island (FL):StatPearls Publishing;2025 Jan–.

2.  Phadnis P, Rathoriya SG, Singhal R, Choudhary V. Descriptive assay of the clinico-morphological characteristics of dermatoses presenting with reticulate pigmentation. Our Dermatol Online. 2023;14:372-9.

3.  Bimbi C, Brzezinski P. Laptop-induced erythema ab igne:A case report. Our Dermatol Online. 2014;5:430-1.

4.  van Rensburg R, Reuter H. Abdominal erythema ab igne:Beyond the rash. Clin Rheumatol. 2024;43:2351-2.

5.  Wipf AJ, Brown MR. Malignant transformation of erythema ab igne. JAAD Case Rep. 2022;26:85-7.

6.  Dessinioti C, Katsambas A, Tzavela E, Karountzos V, Tsitsika AK. Erythema ab igne in three girls with anorexia nervosa. Pediatr Dermatol. 2016;33:e149-50.