Can You Diagnose the Lesions on This 21-Year-Old Woman’s Lower Extremities After She Returned from the Philippines?

Correct answer: B. Ecthyma

The patient’s cutaneous findings and associated systemic inflammatory features were most consistent with an infectious etiology. Given the patient’s recent travel history to the Philippines and exposures to lake and ocean water, the pathogens most likely causing the skin and soft tissue infection were typical bacteria versus atypical mycobacteria or fungal organisms. However, the patient’s differential diagnosis was broad and included parasitic, viral, and inflammatory causes. The confirmation of the GAS infection on tissue culture, associated systemic inflammatory response, and speed of progression makes ecthyma the correct diagnosis.

Bacillary angiomatosis was considered, but opportunistic infections were less likely given that the patient was immunocompetent. Elastosis perforans serpiginosa was also considered, but the patient was not on any medications and did not have any comorbidities to make this a likely diagnosis. Atypical infections including mycobacterium were part of the differential diagnosis, however due to the rapidity of progression and associated sepsis this was not favored.

Treatment and management. The patient was started on IV vancomycin (750 mg/100 mL every 8 hours) and ceftriaxone (2 g/100 mL every 24 hours), both for 3 days, given our concern for severe skin and soft tissue infection with systemic inflammatory response pending culture results. Her vitals stabilized, fever resolved, and leukocytosis improved. After the tissue culture results were obtained, the patient was switched from IV antibiotics to a 14-day course of amoxicillin-clavulanate tablets (875-125 mg tablets twice per day) and discharged.

Outcome and follow-up: The patient returned to the dermatology clinic after completing her 14-day course of amoxicillin-clavulanate tablets. Her skin examination displayed marked improvement. Hemorrhagic crusts were scattered on her legs, and post-inflammatory hyperpigmented macules with fresh re-epithelialization were present on her back. Given that there was no concern for ongoing infection, the patient was instructed to regularly apply petroleum jelly to the lesions to aid healing.

Discussion. Ecthyma is a cutaneous pyogenic infection beginning as a pustule that, once ruptured, leaves a crusted ulcer that extends deep into the dermis.¹ Ecthyma is often associated with trauma, insect bites, and immunosuppression.2 While this patient had no history of immunosuppression, she was exposed to both fresh and saltwater and various types of flies while overseas.

While ecthyma is commonly caused by GAS and S. aureus in the United States, a case of ecthyma due to Moraxella and S. epidermidis infections has been reported.³  Ecthyma generally presents as an isolated ulcer with an erythematous border, but rare progression to necrotizing fasciitis has been described.^2,4 Our patient presented with multiple morphologies, including crusted pustules and papulonodules on her lower extremities, which are a common presentation of ecthyma, as well as clustered superficial erosions on the lower back that clinically mimicked viral infection such as VZV or HSV.

Despite extensive travel and environmental exposures, the patient’s lesion morphology, distribution, and clinical course were not suggestive of water-borne or tropical infections. Instead, the findings were most consistent with ecthyma due to common cutaneous pathogens, underscoring the importance of prioritizing clinicopathological correlation over exposure history alone. This case highlights that clinicians should refrain from prematurely excluding common diagnoses, even when patients present with multiple exposures or travel histories that raise suspicion for atypical diseases.

AUTHORS:
Peyton Yee, BS¹ • Olivia Cohen, MD, MsPH² • Barrett J. Zlotoff, MD²

AFFILIATIONS:
¹University of Virginia School of Medicine, Charlottesville, Virginia
²Department of Dermatology, University of Virginia Medical Center, Charlottesville, Virginia

CITATION:
Yee P, Cohen O, Zlotoff BJ. Can you diagnose the lesions on this 21-year-old woman’s lower extremities after she returned from the Philippines? Consultant. Published online February 5, 2026. doi: 10.25270/con.2026.02.0000001
Received Nov. 5, 2025. Accepted Nov. 12, 2025.

DISCLOSURES:
The authors report no relevant financial relationships.

ACKNOWLEDGEMENTS:
None.

CORRESPONDENCE:
Peyton Yee, BS, University of Virginia Department of Dermatology, 1221 Lee St., Charlottesville, VA 22903 (Email: dhp3nh@virginia.edu)

References

1. Empinotti JC, Uyeda H, Ruaro RT, Galhardo AP, Bonatto DC. Pyodermitis. An Bras Dermatol. 2012;87(2):277-284. doi:10.1590/s0365-05962012000200013
2. Török ME, Conlon CP. Skin and soft tissue infections. Medicine. 2013;41(12):709-715. doi:10.1016/j.mpmed.2013.10.001
3. Rabionet A, Vivar KL, Mancl K, Bennett AE, Shenefelt P. Ecthyma associated with Moraxella and Staphylococcus epidermidis. JAAD Case Rep. 2016;2(6):473-475. Published 2016 Dec 5. doi:10.1016/j.jdcr.2016.09.017
4. Nukaly HY, Alhawsawi WK, Nassar JY, et al. Ecthyma amidst the global monkeypox outbreak: A key differential? -A case series. IDCases. 2024;39:e02125. Published 2024 Dec 15. doi:10.1016/j.idcr.2024.e02125

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