Race for the Case answers

Race for the Case Spring 2024 by Jessica Forbes Kaprive, DO

A 16-year-old Middle Eastern female with no past medical history presents with a complaint of skin discoloration, located on the left posterior neck for approximately three years. The patient reports that the discoloration has recently become more noticeable, progressively darker and spreading toward the anterior neck and posterior shoulder blade on the left side. She denies any symptoms associated with the rash such as pruritus or burning. She also denies a personal or family history of any prior dermatologic conditions, autoimmune diseases, or thyroid disease. Review of symptoms is significant for travel history to the Middle East in the past two years where she previously lived.

1. What is the most likely diagnosis?
Answer: The clinical photographs demonstrate erythema dyschromicum perstans (EDP), or ashy dermatosis. This eruption is asymptomatic, usually symmetric, and involves the upper trunk, neck, and proximal extremities. It is usually seen in Fitzpatrick skin types III-IV and has a predilection for Latin Americans.

2. Describe the findings of this condition?
Answer: The findings usually include a gradual onset of slate grey-brown or grey-blue, ovoid macules and patches with an erythematous rim.

3. What are common conditions that one could consider on the differential diagnosis?
Answer: With presentation of reticulated erythematous to slate grey-brown macules and patches, one may also consider confluent and reticulated papillomatosis (CARP), acanthosis nigricans, and lichen planus pigmentosus (LPP). The diagnosis of EDP should not be based on histologic findings alone as there is significant histologic overlap with LPP with increased number of melanophages, lymphocytic infiltrate, and basal vacuolar degeneration.

4. What is the clinical course and prognosis for this condition?
Answer: 70% of cases in children resolve within 2-3 years; adult disease course is typically more persistent.

5. What is the treatment of choice for ashy dermatosis?
Answer: Clofazamine is the treatment of choice. NB-UVB, Dapsone and other treatments similar to lichen planus treatments may be used. Lasers are largely ineffective and may cause significant post-inflammatory hyperpigmentation and fibrosis.

References

1. Alihkan A, Hocker TLH. Review of Dermatology, 3.3 Interface Dermatitis. General Dermatology. Elsevier; 2017.

2. Chang M. W. Disorders of hyperpigmentation. In: Bolognia J. L., Schaffer J. V., Cerroni L., editors. Dermatology. 4th. Amsterdam, Netherlands: Elsevier; 2018. pp. 1116–1117.

3. Leung N, Oliveira M, Selim MA, McKinley-Grant L, Lesesky E. Erythema dyschromicum perstans: A case report and systematic review of histologic presentation and treatment. Int J Womens Dermatol. 2018 Sep 27;4(4):216-222. doi: 10.1016/j.ijwd.2018.08.003. PMID: 30627620; PMCID: PMC6322153.