Inoculation blastomycosis
=========================

* Stacey Bernstein
* Susan Richardson

Robert Lester and colleagues have reported 2 cases of infection with *Blastomyces dermatitidis* acquired in Toronto.1 They conclude that the infections were due to inoculation blastomycosis. This seems unlikely, especially in the first case.

The first patient developed a skin lesion that was not precipitated by any significant trauma, followed by multiple, multifocal skin lesions at a distant site. The rarity of inoculation blastomycosis, coupled with the clinical presentation, suggests that this woman suffered from an infection that disseminated from a primary pulmonary portal of entry. This may occur in the absence of active pulmonary disease. In addition, skin disease is a marker for multiorgan infection.2 In this patient, it is interesting to note that no bone scans or radiographs were taken to look for musculoskeletal involvement. The authors suggest that these tests were unwarranted and would have been arduous. After the skin, bone is the second most common focus of extrapulmonary infection and the patient may be asymptomatic. Recent guidelines for the management of patients with blastomycosis recommend that patients with mild to moderate disseminated disease be treated with itraconazole for at least 6 months.3 The higher response rate in bone infection mandates treatment with itraconazole for at least 1 year.3 We suggest that this patient was underinvestigated and potentially undertreated because she received itraconazole for only 4 months.

The second patient was scratched by a cat 2 months before the onset of her skin lesion. Although blastomycosis is known to occur in cats, it is much rarer than in dogs. Furthermore, all reported dog-associated cases of inoculation blastomycosis have been due to the bite of a dog that was ill with advanced pulmonary disease.4 In this case, the cat was well, it resided in a nonendemic area and there was no history of a bite; all of these factors significantly decrease the possibility that the cat was the source of the infection.

We recommend caution in diagnosing inoculation blastomycosis before a more comprehensive search is done to rule out systemic disease in patients without active pulmonary infection.

## References

1.  1. Lester RS, DeKoven JG, Kane J, Simor AE, Krajden S, Summerbell RC. Novel cases of blastomycosis acquired in Toronto, Ontario. CMAJ 2000;163(10):1309-12.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czoxMToiMTYzLzEwLzEzMDkiO3M6NDoiYXRvbSI7czoyNDoiL2NtYWovMTY0LzEyLzE2NjQuMi5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 

2.  2. Chapman SW. Blastomyces dermatitidis. In: Mandell GL, Bennett JE, Dolin R, editors. *Principles and practices of infectious diseases*. 5th ed. Philadelphia: Churchill Livingstone; 2000. p. 2733-44.
    
    

3.  3. Chapman SW, Bradsher RW, Campbell GD, Pappas PG, Kauffman CA. Practice guidelines for the management of patients with blastomycosis. Clin Infect Dis 2000;30:679-83.
    
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4.  4. Gnann JW, Bressler GS, Bodet CA, Avent CK. Human blastomycosis after a dog bite. Ann Intern Med 1983;98:48-9.
    
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