A 67-year-old woman with insulin-dependent diabetes mellitus, longstanding chronic venous insufficiency, peripheral vascular disease and associated chronic leg ulcers presented to our clinic with a rash shortly after a ray amputation of the first toe and metatarsal due to osteomyelitis. She initially developed severe erosive pustules adjacent to the amputation site, but quickly developed disseminated erosive pustules and erythema on many sites, which created severe burning pain. The pustular erosions on her feet were so severe that amputation was discussed prior to our dermatological consultation.
Physical examination revealed large erosive plaques with overlying, almost confluent, pustules and hyperkeratotic debris with a surrounding serpiginous border of erythema present on the distal and dorsal foot, inguinal area, upper arm in area of prior burn, scalp, and dorsal tongue. In parts, the surrounding non-lesional skin was atrophic ().
Clinical photographs of the patient at presentation. A and B: left foot, C: inguinal region and D: tongue.
Histopathological examination showed a hypertrophic epidermis with a diffuse dermal inflammatory infiltrate composed of mainly neutrophils and occasional lymphocytes, macrophages and eosinophils. There were prominent large eosinophilic and neutrophilic abscesses within the dermis (). A direct immunofluorescence assay was negative.
Haematoxylin and eosin staining of a skin biopsy taken from the patient’s groin at presentation. (A) Low-power magnification × 40; (B) medium-power magnification × 100.
Laboratory studies were largely normal, but showed a moderate peripheral blood leukocytosis with increased neutrophils, lymphocytes, and eosinophils and slightly elevated C-reactive protein and haemoglobin A1c (7.2%; >6.5% is consistent with diabetes). The patient also demonstrated moderate plasma zinc deficiency.
Microbiology revealed mild growth of Staphlococcus aureus and Streptococcus agalactiae, which were consistent with benign colonization. Fungal cultures were negative. X-ray studies of her feet and toes were unremarkable. Vascular Doppler ultrasound studies of the patient’s lower extremities revealed bilateral chronic venous insufficiency without signs of deep venous thrombosis. Neurology consultation confirmed the presence of severe diabetic neuropathy.
Prior to presenting to our clinic, the patient was treated with local topical therapies, including antifungal creams and antiseptic solutions and oral antibiotics, which were unsuccessful. Initially, we began both local therapy with daily antiseptic solution and potent glucocorticoids (very potent) in conjunction with oral zinc replacement and oral fluconazole (which was discontinued once mycology results were proven negative). After 6 weeks of this regimen, a slight improvement was observed; however, many areas remained affected and patient began to develop new erosions and pustules in other areas.
Due to the progression of the EPD during aggressive topical treatments and the disseminated nature of this patient’s disease, we considered a trial of oral dapsone. Dapsone was started at 50 mg orally (first week twice a day, then three times a day) in combination with vitamin C (1,000 mg daily). Within a few days, a significant improvement in all skin lesions was observed. A sustained and complete remission of all erosive pustules was observed 6 weeks after initiation of dapsone therapy. We continued treatment with dapsone 50 mg twice daily for an additional 2 months after the skin had cleared before discontinuation. The patient remained clear of any skin lesions at follow-up examinations at 3, 6, and 12 months post-treatment.