University of Alabama at Birmingham

2013 Case #3

Universidad Peruana Cayetano Heredia
The following patient was seen in the outpatient department of the 36-bed Tropical Disease Unit at Cayetano Heredia National Hospital.

Image A for 02/18/2013History: 80 yo female presenting with a 14-month history of a single painless erythematous papule over the right leg that subsequently ulcerated over less than one week. Since then there has been progressive enlargement of the ulcer with purulent discharge and mild edema surrounding the lesion. Treated locally with herbal remedies with no improvement. An initial biopsy at an outside hospital was non-diagnostic. Oral antibiotics were prescribed with no improvement. No fever or constitutional symptoms. No antecedent trauma. No past medical history.

Epidemiology: Born and lives at 2500m in the highlands of Ayacucho (southeast of Lima). Farmer grows corn and potatoes, and has cows, pigs, dogs and cats. No known TB exposures; no HIV risk factors.

Physical Examination: Afebrile. Normal exam except for the cutaneous lesion on the right leg [Image A]. No hepatosplenomegaly or lymphadenopathy.

Laboratory Results: Hb 12 mg/dl; WBC 7800 (normal differential); ALT 32 (N); normal glucose and creatinine. Normal chest X-ray.

Diagnosis: Sporotrichosis due to Sporotrix schenkii.
Images BCD for 02/18/2013 DiscussionDiscussion: Sporothrix schenkii was cultured [Images B, C] from a biopsy from the border of the ulcer, the best place to sample for both sporotrichosis and leishmaniasis. In culture of scrapings, aspirates or biopsy material on Sabouraud’s agar, S. schenkii grows very easily and rapidly when present. Smears or aspirates from the lesions in sporotrichosis are usually negative on direct examination (not done in this case) and no useful serology is available. AFB, Giemsa, and PAS stains of the biopsy were negative and a PCR and cultures for Leishmania were negative. The patient had been referred to us initially for treatment of presumed leishmaniasis and the ulcer is more characteristic of cutaneous leishmaniasis. This case reinforces the difficulty in making a clinical distinction between the two diseases and each must be definitively investigated in every nodular or ulcerative lesion seen in Perú.

The differential diagnosis of nodular or ulcerated lesions in Perú with or without lymphocutaneous spread includes leishmaniasis, sporotrichosis, atypical mycobacteria, and nocardiosis. Sporotrichosis is always an important consideration in areas such as Perú even where leishmaniasis is much more common. In normal hosts, linear sporotrichoid lesions on an extremity would be the most common presentation of sporotrichosis [see Gorgas Case 2008-01]. In normal hosts, extracutaneous manifestations of sporotrichosis include osteoarticular, meningeal, and pulmonary sporotrichosis. These are usually seen in immunocompromised hosts and in alcoholics. In the last two decades a systemic presentation restricted almost exclusively to HIV patients has been described [see Gorgas Case 2011-02 ; Curr Fungal Infect Rep. 2011;5(1):42-8].

Environmental reservoirs for S. schenkii include sphagnum moss (including wood or plants contaminated by moss), decaying vegetation, hay, soil and masonry. Outdoor work including farming, construction, gardening, and having a cat are risk factors [Clin Infect Dis. 2004;38(4):529-35 and Clin Infect Dis. 2003;36(1):34-9]. Acquisition is generally by local inoculation. Sporotrichosis is distributed worldwide but most cases are reported from the Americas and Japan. Most cases are sporadic or occur in self-limited clusters due to some point source exposure. The area around Abancay, Perú (not where this patient lives) has recently been, perhaps uniquely, identified as an area where sporotrichosis is not only entrenched but is hyperendemic with annual incidence rates of up to 60 per 100,000 population [Clin Infect Dis. 2003;36(1):34-9 and Clin Infect Dis. 2000;30(1):65-70].

Guidelines for treatment of sporotrichosis have been released by the Infectious Diseases Society of America [Clin Infect Dis. 2007;45(10):1255-65] and are partly based on work from our Institute. The treatment of choice for lymphocutaneous sporotrichosis is itraconazole, and in severe extracutaneous or disseminated disease amphotericin B can be used. Terbinafine 500-1000 mg po bid has been shown to be effective therapy [Mycoses. 2004;47(1-2):62-8]. Posaconazole is the only newer azole to have good in vitro activityagainst S. schenckii. Fluconazole at higher doses (400-800 mg daily) has demonstrated some activity for lymphocutaneous sporotrichosis, but voriconazole, ravuconazole and the echinocandins are ineffective against S. schenckii though some are active against other Sporothrix species.

In the reality of poor countries, many patients cannot afford itraconazole or terbinafine. The older but still effective mode of therapy with a saturated solution of potassium iodide (SSKI) is still widely used in practice. SSKI and its clinical use has been reviewed [J Am Acad Dermatol. 2000;43(4):691-7] and we have previously demonstrated the utility of once daily dosing in order to increase compliance [Pediatr Infect Dis J. 1996;15(4):352-4]. The mechanism of action is unknown. SSKI can also be used for entomophthoromycosis caused by Basidiobolus and Conidiobolus. In dermatologic practice SSKI can be used for erythema nodosum, nodular vasculitis, erythema multiforme, and Sweet’s disease. The main adverse effects are gastrointestinal (nausea) and the SSKI can be added to larger volumes of water, juice, or milk for administration. Care must be taken to avoid potassium or iodide toxicity in patients on ACE inhibitors or potassium sparing diuretics, in patients with renal disease, and in patients on medications or with conditions making them unable to autoregulate thyroid hormone production. In areas with high rates of iodine deficiency, such as the Andean highlands, the use of this solution can trigger hyperthyroidism (Jod-Basedow disease).

The patient was started on itraconazole 200mg/day, but did not tolerate it well. The dose was reduced to 100mg with a good clinical response. Image D was taken after 8 weeks of therapy. The plan is for at least 3 months of treatment with itraconazole.