Erosio Interdigitalis_0212 Derm Dx
A 33-year-old otherwise healthy male presents complaining of foul-smelling, itchy and macerated skin between his third and fourth toes. He is not sure how long he has had the problem.
The patient works as a meat-packer and wears waterproof rubber boots as part of his work uniform. He has tried washing between his toes with antibacterial soap, but the skin has not improved. Family medical history is non-contributory, and upon examination, the patient presents as a well-developed, well-nourished male in no acute distress. Physical exam is significant only for foul-smelling maceration and peeling of the skin between his third and fourth toes. What’s your diagnosis?
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Erosio interdigitalis blastomycetica (EIB) is latin for “erosion between the digits caused by a budding fungus.” The condition presents as macerated skin in the webs of the fingers or toes and can extend to the sides of the digits. In the center of the lesion there is fissuring. The macerated skin eventually peels away leaving a denuded area. Patients with EIB may complain of itching, pain and/or a foul smell.
EIB is caused by the fungus Candida albicans, sometimes with an associated gram-negative bacterial infection. Moisture is a predisposing factor and individuals who perform frequent, wet work are at risk. On the hands, EIB nearly always affects the third web, between the middle and the ring fingers. On the feet, the fourth interspace is most frequently affected. Multiple web spaces may be involved. In our patient, the occlusive rubber boots were likely a predisposing factor.1, 2
EIB diagnosis is generally made clinical findings including itchy, painful and foul smelling maceration with erosions in the interdigital web spaces. Culture can be performed, although it is rarely required.
Tinea pedis can present similarly but will not have the characteristic “yeast” smell of EIB. Erythrasma, due to Corynebacterium minutissimum is the most common bacterial infection of the foot, and also may present with maceration and fissuring. However, erythrasma is usually asymptomatic and therefore can be distinguished from EIB, which is invariably itchy or painful. Additionally, erythrasma has a coral red fluorescence when examined with an ultraviolet Wood’s lamp, whereas EIB will not fluoresce.1, 2
EIB treatment includes topical anticandidal medications such as topical miconazole powder. As Candida requires moisture to survive, patients must attempt to keep the affected area as dry as possible. In our practice, we find that patients with toe disease benefit from the use of toe spacers to separate the toes and promote drying. Toe spacers can be found at most pharmacies.1, 2
Adam Rees, MD, is a graduate of the University of California Los Angeles School of Medicine and a resident in the Department of Dermatology at Baylor College of Medicine in Houston.
1. Bolognia J, Jorizzo JL, Rapini RP. “Chapter 76: Fungal Diseases.” Dermatology. St. Louis, Mo.: Mosby/Elsevier, 2008.
2. James WD, Berger TG, Elston DM et al. “Chapter 15: Diseases resulting from fungi and yeasts.” Andrews’ Diseases of the Skin: Clinical Dermatology. Philadelphia: Saunders Elsevier, 2006.