Non-Healing Finger Ulcers in 2 Teen Boys

Two patients, two finger ulcers. Potential diagnoses: Coccidiomycosis; atypical mycobacterium; sporotrichosis; orf virus. Could be any of these, could be none of these.

First obtain a complete history and perform a thorough physical examination. Then, order laboratory tests where relevant.

Patient #1. 18-year-old male with 3-month history of “a worsening sore on my hand.” Has been seen in the ER and two primary care clinics and was prescribed various antibiotics.

Lesion started as a small, firm, dusky papule on left first finger that slowly enlarged and ulcerated.1-2 weeks later, several erythematous, minimally painful nodules erupted on the left forearm.

History: This happened while he was working a summer job as a landscape assistant, before he began studies at a university near his home in southern California.

Physical examination is significant for: A well-developed 3-cm nodule – it is violacious, has central ulceration with undermined edges. There is some crusting located on his left first finger. There are 4 minimally tender 2- 3-cm nodular lesions on his left forearm proximal to the lesion described.

Finger lesion: violacious nodule with undermined edges and some crusting.

Nodules on forearm, minimally tender 2- 3-cm in diameter.

The most likely diagnosis? Coccidiomycosis; atypical mycobacterium; sporotrichosis; orf virus; any of these; none of these; or, not enough information to formulate a diagnosis.

Correct diagnosis: Sporotrichosis.

Sporotrichosis: Dimorphic aerobic fungi -

Sporotrichum schenckii.

Granulomatous subcutaneous mycoses found in decaying vegetable matter and soil. Found in roses, sphagnum moss, and marsh hay, as well as other plant materials.

Sporotrichosis: 3 forms: Lymphocutaneous (most common); fixed cutaneous; extra-cutaneous (pulmonary, systemic)

Lymphocutaneous sporotrichosis. Break in skin-->infection spreads to regional lymph nodes-->Initial lesion is painless papule or vesicle at inoculation site-->induration/ purplish-red at site-->ulceration-->crusting + seropurulent drainage-->freely mobile, non-tender subcutaneous nodules. NB: Patients not systemically ill.

Sporotrichosis. Differential Diagnosis: Atypical TB, localized granulomas, bacterial diseases, syphilis, cat scratch, Leishmaniasis, TB, anthrax, blastomycosis, tularemia, nocardia, Orf virus.

Sporotrichosis. Making the diagnosis. Culture draining lesions - fungus rarely demonstrable by scrapings. Culture drainage, or perform biopsy, punch biopsy and request direct immunofluorescence. Latex slide agglutination - greatest sensitivity and specificity. Referral to dermatology may be preferred.

Sporotrichosis. Treatment: Infectious Diseases Society of America guidelines (2007): Itraconazole is first line treatment, PO y and for 3-6 months. Oral potassium iodide* is second line (traditional treatment): dosing 5 drops PO TID to start; gradually ↑ to 25-40 drops/day-until ↑ salivation, burning in mouth, or patient c/o headaches. Continue 4-6 weeks after lesion is resolved.

While the IDSA guidelines are simplified for ALL practitioners, we might prefer to utilize our infectious disease colleagues for the confirmation of the diagnosis, treatment schedules, etc.

Patient #2. Also an 18-year-old male with 3-month history of “a worsening sore on my hand.” Has been seen in the ER and two primary care clinics and was prescribed various antibiotics.

History: The lesion started as a small abrasion on left proximal thumb that slowly enlarged and ulcerated. PMH: No exposure to: cats, rabbits, farm animals; no diabetes; denies ETOH; not sexually active; no sickle cell disease; no significant travel history. Lives in San Diego; cleans fish tanks at a pet shop for work.

Ulcerated 3-cm lesion on proximal thumb with scant, clear discharge. This is the only physical finding.

Differential diagnosis for ulcers on the hand: Atypical TB, localized granulomas, bacterial diseases, syphilis, cat scratch, Leishmaniasis, TB, anthrax, blastomycosis, tularemia, nocardia, Orf virus.

Most likely diagnosis?

Correct diagnosis: Atypical mycobacterium.

Atypical mycobacterium (swimming pool granuloma, fish tank granuloma). Culture-proven

Mycobacterium marinum.

Group I photochromogen; acid-fast non-motile bacillus; grows best at 30-33C with intermediate growth at 37C, thus acral distribution; Mycobactosel (Lowenstein-Jensen medium) - cream colored colonies in dark incubation will turn yellow after 1 -2 days exposure to light.

Mycobacterium marinum

Atypical mycobacteria, ubiquitous in aquatic environments worldwide, in saltwater and freshwater. Clinical history preceding infection may involve trauma followed by exposure to water, handling fish or shellfish. Rarely,

M. marinum

may cause deeper infections

Atypical mycobacterium treatment: 1. Relatively resistant to traditional anti-tuberculosis medications2. Synthetic tetracyclines – questionable success, but… see #4. 3. Septra (trimethoprim/sulfamethoxazole) questionable success. 4. Ciprofloxacin has had some success, but…. see #5. 5. Applied heat seems to be the most helpful treatment in conjunction with trials of the above medications.