“There’s bruising on my child’s legs”—an interesting sequela

The field of dermatology has historically focused on disease presentation in predominantly white patients, leading to knowledge gaps in our understanding of the presentations, variations, and treatment responses of various skin conditions in patients of color (1). We describe one such case: a previously healthy, fully immunized 12-year-old African American female presented to the emergency department with 1 day of “bruising” and pain in her lower legs. Examination revealed a symmetrical reticulated pattern of hyperpigmentation on the bilateral lower extremities (Figures 1,2). Differential diagnosis included infectious and hematologic etiologies including immune thrombocytopenia, livedo reticularis, microangiopathic process, trauma (accidental or nonaccidental), and immunoglobulin A (IgA) vasculitis. Laboratory workup was largely unremarkable, including complete blood count, international normalized ratio, partial thromboplastin time, and peripheral blood smear. On re-evaluation and further questioning, she disclosed sitting in front of a heater over the past few days with her legs directly exposed to the heat, confirming the final diagnosis of erythema ab igne (EAI).

Figure 1 Clinical photograph illustrating EAI in a 12-year-old patient. The image depicts a reticulated pattern of hyperpigmentation localized to the bilateral lower legs, consistent with the characteristic appearance of EAI secondary to chronic exposure to heat sources in a patient with darker skin. EAI, erythema ab igne.

Figure 2 The image captures a wider view of the affected area, showcasing the reticulated pattern of hyperpigmentation extending across the lower legs and lack of characteristic erythema.

EAI results from prolonged exposure to direct heat or infrared radiation, which is thought to denature DNA of squamous cells in the epidermis and induce injury to the superficial vascular plexus (2). The reticulated appearance results from vasodilation of the plexus with subsequent deposition of hemosiderin and melanin (2). Histopathologic findings classically demonstrate basal vacuolar degeneration and dystrophy/atrophy of the epidermis (3,4). Additionally, there is often atypical cells in the epidermis, similar to actinic keratosis, and an accumulation of dermal elastic tissue (2,3). While the primary cause of EAI is heat exposure, a patient may have underlying conditions, such as chronic pain, arthritis, adenomyosis, endometriosis, metastatic malignancy, or pancreatitis which may predispose them to use heat for pain relief (2). Moreover, diagnoses hallmarked by cold intolerance or circulatory issues, like hypothyroidism and Raynaud’s phenomenon, may also lead to increased risk of this condition (3). The rash typically resolves in weeks to months, though this depends on factors like the intensity and duration of heat exposure (4).

It is important to note that like many other skin conditions, EAI may present differently in patients of color compared to patients with lighter skin tones. A hallmark of this diagnosis is hyperpigmentation, which may be more pronounced in patients with darker skin, appearing as deep brown or black patches that can be confused with ecchymosis (5). While potentially similar in appearance, the presence or lack of reticulation may help distinguish these underlying etiologies. Moreover, a thorough anamnesis, especially in pediatric patient populations, can be used to establish potential exposures and chronology of these symptoms (4). Erythema, another key feature of this rash, may be less noticeable or absent in patients with darker skin (5). It is crucial for providers to be aware of these variations in presentation based on skin color to ensure accurate, timely diagnosis and appropriate management (1).

Acknowledgments

The authors gratefully acknowledge the permission of this patient and their family to share the information contained in this article.

Funding: None.

Footnote

Provenance and Peer Review: This article was a standard submission to the journal. The article has undergone external peer review.

Peer Review File: Available at https://jeccm.amegroups.com/article/view/10.21037/jeccm-24-106/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jeccm.amegroups.com/article/view/10.21037/jeccm-24-106/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent for the publication of this patient’s information and consent for the publication of corresponding images was provided by the patient’s mother. A copy of the written consent is available for review by the editorial office of this journal.

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References

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