eMedicine Specialties > Dermatology > Environmental

Erythema Ab Igne

Robert S Bader, MD, Assistant Clinical Professor, Department of Dermatology, Hahnemann Hospital

Updated: Feb 27, 2007

Introduction

Background

Erythema ab igne (EAI) occurs in skin that is chronically and repeatedly exposed to infrared radiation. EAI results in persistent, reticulate, erythematous patches; telangiectasia; and hyperpigmentation.

Pathophysiology

EAI is caused by chronic repeated exposure to moderate heat from an external heat source. The exposure, which need not be of long duration, results in cutaneous hyperthermia in the range of 43-47°C, which, in turn, results in histopathologic changes similar to those seen in solar-damaged skin. Although the pathogenic mechanisms in EAI are poorly understood, one study has shown that moderate heat acts synergistically with ultraviolet radiation to denature DNA in squamous cells in vitro.

Frequency

United States

Rare

Mortality/Morbidity

Chronic repeated exposure to infrared radiation may result in changes similar to those seen with chronic repeated ultraviolet radiation. Thermal keratosis, squamous cell carcinoma in situ, and squamous cell carcinoma have been reported in patients after chronic exposure to infrared radiation. In one 90-year-old woman with EAI, Merkel cell carcinoma developed adjacent to squamous cell carcinoma.

Sex

Women, in particular those who are overweight, are affected more often than men.

Clinical

History

Commonly, patients report mild pruritus and burning.

Physical

Mild elevation of skin temperature initially results in mild, transient, often reticulated erythema. With prolonged and repeated exposure, areas of reticular erythema persist and, in time, become livid and hyperpigmented. Rarely, affected areas may become bullous or hyperkeratotic; in patients with severe long-standing EAI, poikilodermatous changes may result. Some believe that a bullous variant of EAI exists, in which bullae and crusts are present on a base of reticulated erythema.

Causes

The following have been reported as heat sources that resulted in the development of EAI:

Open fires reportedly result in EAI.
- Typically, EAI affects the legs of women aged 40-70 years who use indoor fire as a heat source.
- EAI reportedly affects the face and/or palms of cooks who work over an open fire.
Some patients use a heat source (eg, heating pad, hot water bottle, heated recliner) to relieve chronic pain. In these patients, determine the etiology of the pain.
- Heating pads and/or hot water bottles: EAI occurs in patients with pain associated with either primary or metastatic malignancy, as well as with pain associated with chronic pancreatitis.
- Heated recliners (reclining chairs): EAI has been reported in patients with chronic lower back pain.
- A car heater reportedly caused EAI in one patient.
- The application of heated popcorn kernels applied to the skin to reduce arthritic pain caused EAI in one patient.
More recently, using laptop computers while they are propped on the legs has resulted in the development of EAI. Some laptop computers can generate significant heat that can result in EAI when placed on the lap for prolonged periods.

Differential Diagnoses

Acanthosis Nigricans

Workup

Procedures

Perform a 3- or 4-mm punch biopsy if the diagnosis is uncertain.

Histologic Findings

In early lesions, epidermal atrophy with loss of the rete ridges is seen. Later, melanin incontinence occurs with melanophages present in the upper dermis.

Collagen degeneration and a relative increase in dermal elastic tissue are seen. In contrast to solar elastosis, this is not basophilic on hematoxylin and eosin–stained specimens.

Telangiectasis within the papillary dermis and occasional hemosiderin may be seen more commonly on the legs.

Some patients show focal or confluent hyperkeratosis, dyskeratosis, keratinocyte atypia, and, occasionally, melanocyte atypia.

Treatment

Surgical Care

In patients with chronic EAI that results in hyperpigmentation, photothermolysis using the Nd:YAG, ruby, or alexandrite laser may improve the appearance of these lesions.

Activity

Cessation of chronic heat exposure is paramount. In mildly affected patients with little or no pigmentary change, their condition may resolve within several months.

Follow-up

Further Outpatient Care

As in patients with chronic solar damage, monitor patients with EAI at regular intervals for possible development of thermal keratosis, squamous cell carcinoma in situ, and squamous cell carcinoma. In addition, although not yet reported, other cutaneous malignancies (eg, malignant melanoma) feasibly may develop within the affected areas.

Prognosis

Early changes, such as erythema and little or no hyperpigmentation, may resolve within several months.
Chronic and repeated exposure to heat may result in such permanent changes as hyperpigmentation and atrophy.
In addition, thermal keratosis, squamous cell carcinoma in situ, and squamous cell carcinoma have been reported within these lesions.

Patient Education

Explain the etiology of the disorder to patients, and emphasize that the cessation of heat exposure is paramount.
Inform patients about the possibility of malignant degeneration in the affected areas. Educate patients about detection and the need for prompt treatment.

Miscellaneous

Medicolegal Pitfalls

Failure to monitor patients regularly and to inform them of the possibility of malignant degeneration (eg, thermal keratosis, squamous cell carcinoma in situ, squamous cell carcinoma)
Failure to determine the etiology of pain in patients who use heat to relieve chronic pain since EAI reportedly has occurred in patients with primary or metastatic malignancies and in patients with chronic pancreatitis

References

Arrington JH 3rd, Lockman DS. Thermal keratoses and squamous cell carcinoma in situ associated with erythema ab igne. Arch Dermatol. Oct 1979;115(10):1226-8. [Medline].
Ashby M. Erythema ab igne in cancer patients. J R Soc Med. Nov 1985;78(11):925-7. [Medline].
Bilic M, Adams BB. Erythema ab igne induced by a laptop computer. J Am Acad Dermatol. Jun 2004;50(6):973-4. [Medline].
Dellavalle RP, Gillum P. Erythema ab igne following heating/cooling blanket use in the intensive care unit. Cutis. Aug 2000;66(2):136-8. [Medline].
Donohue KG, Nahm WK, Badiavas E, et al. Hot pop brown spot: erythema Ab igne induced by heated popcorn. J Dermatol. Mar 2002;29(3):172-3. [Medline].
Dvoretzky I, Silverman NR. Reticular erythema of the lower back. Erythema ab igne. Arch Dermatol. Mar 1991;127(3):405-6, 408-9. [Medline].
Finlayson GR, Sams WM Jr, Smith JG Jr. Erythema ab igne: a histopathological study. J Invest Dermatol. Jan 1966;46(1):104-8. [Medline].
Hardy JD, Stolwijk JA, Hammel HT, Murgatroyd D. Skin temperature and cutaneous pain during warm water immersion. J Appl Physiol. Sep 1965;20(5):1014-21. [Medline].
Helm TN, Spigel GT, Helm KF. Erythema ab igne caused by a car heater. Cutis. Feb 1997;59(2):81-2. [Medline].
Howe NR, Bader RS. Erythema ab igne. Clin Dermatol. 1998;2:7-8.
Jagtman BA. Erythema ab igne due to a laptop computer. Contact Dermatitis. Feb 2004;50(2):105. [Medline].
Kokturk A, Kaya TI, Baz K, et al. Bullous erythema ab igne. Dermatol Online J. Aug 2003;9(3):18. [Medline].
Meffert JJ, Davis BM. Furniture-induced erythema ab igne. J Am Acad Dermatol. Mar 1996;34(3):516-7. [Medline].
Mohr MR, Scott KA, Rariser RM. Laptop Computer-Induced Erythema Ab Igne:A Case Report. Cutis. 2007;79:59-60.
Mok DW, Blumgart LH. Erythema ab igne in chronic pancreatic pain: a diagnostic sign. J R Soc Med. Apr 1984;77(4):299-301. [Medline].
Mucklow ES, Freeman NV. Pancreatic ascites in childhood. Br J Clin Pract. Jun 1990;44(6):248-51. [Medline].
Peterkin GA. Malignant change in erythema ab igne. Br Med J. Dec 31 1955;2(4956):1599-602. [Medline].
Roth D, London M. Acridine probe study into synergistic DNA-denaturing action of heat and ultraviolet light in squamous cells. J Invest Dermatol. Oct 1977;69(4):368-72. [Medline].
Sahl WJ, Taira JW. Erythema ab igne: treatment with 5-fluorouracil cream. J Am Acad Dermatol. Jul 1992;27(1):109-10. [Medline].
Shahrad P, Marks R. The wages of warmth: changes in erythema ab igne. Br J Dermatol. Aug 1977;97(2):179-86. [Medline].

Keywords

erythema ab igne elastosis, ephelis ab igne, erythema à calore, toasted skin syndrome, erythema a calore

Contributor Information and Disclosures

Author

Robert S Bader, MD, Assistant Clinical Professor, Department of Dermatology, Hahnemann Hospital
Robert S Bader, MD is a member of the following medical societies: American Academy of Dermatology, American Society for Dermatologic Surgery, and American Society for MOHS Surgery
Disclosure: Nothing to disclose.

Medical Editor

Marjan Garmyn, MD, PhD, Professor, Faculty of Medicine, Katholieke Universiteit Leuven, Belgium; Chair and Adjunct Head, Department of Dermatology, University of Leuven, Belgium
Disclosure: Nothing to disclose.

Pharmacy Editor

David F Butler, MD, Professor of Dermatology, Texas A&M University College of Medicine; Director, Division of Dermatology, Scott and White Clinic; Director Dermatology Residency Training Program, Scott and White Clinic
David F Butler, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Medical Association, American Society for Dermatologic Surgery, American Society for MOHS Surgery, Association of Military Dermatologists, and Phi Beta Kappa
Disclosure: 3M Pharmaceutical Grant/research funds Other; Graceway Pharmaceuticals Grant/research funds Other

Managing Editor

Edward F Chan, MD, Clinical Assistant Professor, Department of Dermatology, University of Pennsylvania School of Medicine
Edward F Chan, MD is a member of the following medical societies: American Academy of Dermatology, American Society of Dermatopathology, and Society for Investigative Dermatology
Disclosure: Nothing to disclose.

CME Editor

Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University
Catherine Quirk, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Dermatology
Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD, Director, Department of Dermatology, Geisinger Medical Center
Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology
Disclosure: Nothing to disclose.

Further Reading