Erythema ab igne (EAI) is a cutaneous rash that is characterized by reticulate erythema and hyperpigmentation with telangiectasia.1 Owing to the rarity of this condition and potential for clinical diagnosis, the incidence and prevalence are unknown. A recent retrospective study reported a mean age of 29 years with a female predominance (2:1).2 It develops secondary to prolonged exposure to mild heat, usually between 43 and 47°C, which is not warm enough to induce thermal burns.3 Historically, it was associated with prolonged exposure to a fire or stove. Typical modern heat sources include heating pads, heated massage chairs, hot water bottles, and laptops.3 In patients with acute or chronic pain syndrome, EAI develops due to the persistent use of heating devices, often for chronic pain.4
CASE REPORTA 42-year-old man with alcohol-induced chronic pancreatitis (Figure 1) presented to clinic for routine follow-up and monitoring of complications, including exocrine pancreatic insufficiency, chronic pancreatitis-related diabetes, and chronic abdominal pain. He reported progressive worsening of a rash over several months. At the time of evaluation, he was smoking 1 pack of cigarettes per day and had been abstinent from alcohol for more than 5 years. He denied any abdominal trauma but stated that he injects subcutaneous insulin in the lower abdomen. On physical examination, his abdomen was diffusely tender, including to light touch, and demonstrated a rash that extended from the waist to the costal margin over the left side of his abdomen (Figure 2). Laboratory evaluation was notable for well-controlled diabetes and mild deficiencies of vitamins A and E. Carbohydrate antigen 19-9 was 31 U/mL (normal ≤37 U/mL).
Figure 1.:Representative coronal image from a computed tomography scan without intravenous contrast demonstrating multiple pancreatic calcifications consistent with chronic pancreatitis.
Figure 2.:Photographs of the abdomen demonstrating evolution of changes related to erythema ab igne at (A) presentation and (B) 6 months and (C) 36 months of follow-up.
During the initial evaluation, he denied the use of a heating device for pain management. However, after leaving the office, he recalled the use of a new electric heating blanket on high settings for 1 month preceding the onset of the rash. In consultation with dermatology, he was diagnosed with EAI clinically, based on the characteristic appearance of the rash and the exposure. As a result, he was advised to discontinue the heating blanket or other sources of topical heat.
In subsequent follow-up visits to the pancreas clinic at 6 months and 3 years after the development of EAI, he continued to have persistence of skin findings despite discontinuation of heating devices (Figure 2). Unfortunately, he continued to experience a chronic abdominal pain syndrome, which is being managed medically with opioid and nonopioid analgesics.
DISCUSSIONEAI can often be diagnosed based on its classical appearance and a history of preceding heat exposure. The rash can occur on any surface and is often asymmetric. The differential for EAI can include livedo reticularis, livedoid vasculitis, cutis marmorata telangiectatica congenita, poikiloderma vasculare atrophicans, and panniculitis.5–8 Initially, there is a blanchable area of erythema, which progresses to the typical reticular, hyperpigmented rash.3
Generally, a biopsy is not required to make this diagnosis; however, when obtained, there are changes of vascular dilatation in the superficial dermis, atypia and necrosis of keratinocytes, and deposition of melanin and hemosiderin in the epidermis.3 Cessation of heat exposure can lead to fading of the rash over weeks to months in the early stage of erythema; however, in some cases (such as this one), hemosiderosis may persist for several years or may be permanent.3 A 2-week treatment with topical 5-fluorouracil has been shown to resolve keratinocyte atypia, but it does not alter the hyperpigmentation.9
EAI and unabated chronic cutaneous heat exposure have resulted in progression to nonmelanoma skin cancers, most often squamous cell carcinoma within the field of exposure.1,3 The latency period of thermal-induced cancers may be greater than 30 years.1 Treatment with 5-fluorouracil is hypothesized to reduce this risk, but long-term follow-up of 5-fluorouracil-treated patients has not been completed.
EAI has been previously reported in other patients with chronic pancreatitis and pancreatic cancer who developed thermal injury because of treating abdominal or back pain related to these conditions.4,10–13 Thus, when this rash is observed, it is important to understand the underlying originator of pain that prompted the use of heat therapy and make efforts to provide alternative strategies for symptom control. Recognition and diagnosis of EAI by gastroenterology consultants may provide an explanation for the rash, sparing patients anxiety or additional, unnecessary diagnostic evaluation.
DISCLOSURESAuthor contributions: J. Bejjani and ML Ramsey: study concept and design, acquisition of data, drafting of the manuscript, critical revision of the manuscript for important intellectual content, and approval of the final manuscript. B. Kaffenberger: acquisition of data, drafting of the manuscript, critical revision of the manuscript for important intellectual content, and approval of the final manuscript. PA Hart: study concept and design, drafting of the manuscript, critical revision of the manuscript for important intellectual content, supervision, and approval of the final manuscript, and is the article guarantor.
Acknowledgement: We thank the patient for their willingness to grant permission to share their story and images to promote education of the medical community on this potentially overlooked condition.
Financial disclosure: None to report.
Informed consent was obtained for this case report.
REFERENCES 1. Kibbi AG, Tannous Z. Skin diseases caused by heat and cold. Clin Dermatol. 1998;16(1):91–8. 2. Ozturk M, An I. Clinical features and etiology of patients with erythema ab igne: A retrospective multicenter study. J Cosmet Dermatol. 2020;19(7):1774–9. 3. Miller K, Hunt R, Chu J, Meehan S, Stein J. Erythema ab igne. Dermatol Online J. 2011;17(10):28. 4. Bunick CG, King BA, Ibrahim O. When erythema ab igne warrants an evaluation for internal malignancy. Int J Dermatol. 2014;53(7):e353–5. 5. Guarneri C, Tchernev G, Wollina U, Lotti T, Vaccaro M. Erythema Ab igne caused by laptop computer. Open Access Maced J Med Sci. 2017;5(4):490–2. 6. Smith T, Nambudiri VE. Erythema ab igne. Cleve Clin J Med. 2018;85(2):96–7. 7. Cabrera Hernández A, Beà Ardebol S, Medina Montalvo S, Trasobares Marugán L. Erythema ab igne. Reumatol Clin (Engl Ed). 2016;12(4):233–4. 8. Borgia F, De Pasquale L, Cacace C, Meo P, Guarneri C, Cannavo SP. Subcutaneous fat necrosis of the newborn: Be aware of hypercalcaemia. J Paediatr Child Health. 2006;42(5):316–8. 9. Sahl WJ Jr, Taira JW. Erythema ab igne: Treatment with 5-fluorouracil cream. J Am Acad Dermatol. 1992;27(1):109–10. 10. Harsch IA. Abdominal erythema ab igne: An “old” finding revisited. Clin Case Rep. 2020;8(7):1315–6. 11. Parker R, Gordon FH. A different cause of erythema ab igne in chronic pancreatitis. Pancreatology. 2008;8(4–5):532. 12. Syed AA, Mecci FN. Medical image. Erythema ab igne. N Z Med J. 2008;121(1276):106–7. 13. Mok DW, Blumgart LH. Erythema ab igne in chronic pancreatic pain: A diagnostic sign. J R Soc Med. 1984;77(4):299–301.
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