TELEDERMATOLOGY READER REPORT
History
Chief complaint: presenting for confirmatory diagnosis of the cutaneous lesion.
History of present illness: A 66-year-old gentleman with chronic back pain presents with a discolored rash on his lower back for several months. He has changed his laundry detergent and body wash and confirms use of his heating pad nightly. For his prior treatment of this skin rash, he has used emollients, over-the-counter hydrocortisone 1% cream, and clotrimazole cream with no improvement. He states that the rash does not hurt or itch. He has no prior biopsy and also no personal or family history of skin cancer or melanoma. There were no other significant laboratory/study findings.
IMAGE QUALITY ASSESSMENT
Fully satisfactory.
TELEDERMATOLOGY IMAGING READER REPORT1
One image was provided for Lesion A. The image shows multiple scattered erythematous, violaceous, and reddish-brown macules, some of which coalesce into a reticulated patch, on the right flank. The reticulated arrangement is most prominent within the lateral aspect of the image (see Figure 1).
INTERPRETATION OF IMAGES
Lesion A Findings
The history and presented lesions are most consistent with the diagnosis of erythema ab igne (EAI).
RECOMMENDATIONS
Skin Care and Treatment Recommendations
No specific therapy is available for EAI. The patient should prevent further exposure to the heat source to reverse the erythema. Removal of the heat source during early stages of the condition may allow for complete resolution of the erythema.
RECOMMENDED FOLLOW-UP
Return to primary provider for reassurance.
Early-stage lesions are self-limited (benign). However, patients with chronic hyperpigmented lesions should be monitored at regular intervals because of the possibility of malignant transformation (i.e., squamous cell carcinoma in situ).
CLINICAL PEARL
EAI is a skin condition caused by repeated exposure to low levels of heat. Heat sources include fireplaces, heating pads, heated reclining chairs, hot water bottles, and electronic devices. Low-grade heat causes dilatation of superficial blood vessels, which initially presents as transient, reticulated, macular erythema. Repeated exposure to the heat source may damage the superficial blood vessels and cause further dilatation as well as hemosiderin deposition, resulting in a reddish-brown reticulated hyperpigmentation (Botten, Langley, & Webb, 2010). The differential diagnosis includes livedo reticularis, cutis marmorata, poikiloderma, and port-wine stain (Beleznay, Humphrey, & Au, 2010). Historically, lesions were seen in individuals sitting in front of open fires for warmth during the winter (Treister-Goltzman & Peleg, 2015). Later, cases included cooks with repeated exposure to stoves, hospital patients with heated blankets, elderly individuals with repeated and prolonged exposure to radiators or fireplaces, and patients with chronic pain using heating pads (Riahi, Cohen, Robinson, & Gray, 2010). Electronic devices, such as laptop computers, have recently been reported to cause EAI (Riahi & Cohen, 2012).
Management involves discontinuing further exposure to the heat source. Early-stage lesions may fade away over several months after ceasing exposure to the causative agent; however, the hyperpigmentation of chronic lesions may persist over many years. Although the prognosis is very good, patients with chronic EAI are at an elevated risk of developing cutaneous malignancies, such as squamous cell carcinoma and Merkel cell carcinoma, within affected areas (Miller, Hunt, Chu, Meehan, & Stein, 2011). Therefore, patients should be monitored regularly for malignant transformation of chronic lesions.
REFERENCES