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Peer Reviewed

What's Your Diagnosis?

What Is Causing This Woman’s Swollen, Red, and Tingling Finger?

Volume 58 - Issue 6 - June 2018

  • Answer: Sporotrichosis

    The differential diagnosis for digital swelling is extensive and can be clinically daunting. Possible etiologies include local injuries such as fractures, tendon injuries, and contusions; infections; and systemic processes such as congestive heart failure (CHF), lymphedema, and rheumatoid arthritis.

    In this patient’s case, it is fairly simple to exclude the macro causes of digital swelling (eg, CHF, kidney failure, liver failure, deep vein thrombosis), since they rarely if ever result in edema of a single digit. The woman’s age and demographics make sickle cell disease unlikely. This leaves the discerning clinician with a number of can’t-miss diagnoses, including fracture, flexor tenosynovitis, and cellulitis. Without deformity, bony tenderness, or an identifiable mechanism, fracture is far less likely. The lack of Kanavel signs in this patient’s case does not support a diagnosis of flexor tenosynovitis. The process of elimination leaves us with cellulitis; however, the physical findings and clinical history are not exactly congruent with this selection. As with so many cases, the determining factor here is the clinical history. Gardening is the key.

    This patient had sporotrichosis, a fungal infection caused by the saprophytic fungus Sporothrix schenckii.

    DISCUSSION

    Occurring in several forms, sporotrichosis is most commonly seen in its cutaneous variety; the pulmonary and disseminated forms typically are discovered only in immunocompromised persons.1,2 The classic clinical course is indolent, with the development of a red, pink, or purple nodule at the site of skin inoculation or trauma (often the prick of a thorn) within 1 to 12 weeks of exposure and subsequent spreading proximally along lymphatic channels.1-3 Sporotrichosis can also occur in a fixed cutaneous form, as it did in this patient’s case, manifesting as a violaceous, reticular rash extending from a nonhealing, painless plaque (the puncture wound).2,4 Lymphangitic spread and satellite lesions will not be seen in such cases.2

    Sporotrichosis is quite rare in the United States, with an annual incidence of only 1 case per million population.2,3 The diagnosis is usually made on a clinical basis alone, but the gold standard method is tissue biopsy and culture.2-4

    Risk factors include gardening, landscaping, farming, berry-picking, horticulture, and carpentry.2 Preventive measures include wearing protective gloves, long sleeves, and long pants, especially during such higher-risk activities.2,3 Sporotrichosis is not contagious.3

    The treatment of choice is an extended course of itraconazole.1-4 Alternative treatments include itraconazole at an increased dosage, terbinafine, or simply applying external heat, since S schenckii grows best at 35°C.1,2 External heat is the preferred treatment in pregnant women, unless the infection is severe or disseminated.1 Amphotericin B is the treatment of choice in cases of disseminated infections.1-4 Spontaneous resolution of sporotrichosis is rare.1

    OUTCOME OF THE CASE

    The patient was started on itraconazole and was scheduled for a next-day follow-up appointment in the plastic surgery hand clinic. At that visit the following day, she reported having developed palpitations, which were attributed to the new medication. Itraconazole was stopped, cephalexin was initiated, and she was referred to the infectious disease clinic the next day, at which time terbinafine was initiated.

    Several months later, at a visit to her primary care provider, she reported complete resolution of symptoms of sporotrichosis.

    Jonathan Frommelt, MD, is an attending physician in the Department of Emergency Medicine at MetroHealth Medical Center in Cleveland, Ohio.

    David Effron, MD, is an associate professor at Case Western Reserve University and an attending physician in the Department of Emergency Medicine at MetroHealth Medical Center in Cleveland, Ohio.

    REFERENCES:

    1. Kauffman CA, Bustamante B, Chapman SW, Pappas PG. Clinical practice guidelines for the management of sporotrichosis: 2007 update by the Infectious Diseases Society of America. Clin Infect Dis. 2007;45(10):1255-1265.
    2. Agudelo Higuita NI. Sporotrichosis. Medscape. https://emedicine.medscape.com/article/228723-overview. Updated August 9, 2017. Accessed April 17, 2018.
    3. Centers for Disease Control and Prevention. Sporotrichosis. https://www.cdc.gov/fungal/diseases/sporotrichosis/index.html. Updated August 18, 2016. Accessed April 17, 2018.
    4. Vásquez-del-Mercado E, Arenas R, Padilla-Desgarenes C. Sporotrichosis. Clin Dermatol. 2012;30(4):437-443.