|Year : 2017 | Volume
| Issue : 2 | Page : 109-111
O Sasikumari, S Anupama
Department of Microbiology, Government Medical College, Thiruvananthapuram, Kerala, India
|Date of Web Publication||26-Dec-2017|
Dr. O Sasikumari
Department of Microbiology, Government Medical College, Thiruvananthapuram, Kerala
Source of Support: None, Conflict of Interest: None
Histoplasma capsulatum is a dimorphic fungus which produces systemic infection, especially in immunocompromised patients. We report a case of histoplasmosis in a patient with diabetes who presented with fever of unknown origin of 1-year duration. He expired due to discontinuation of treatment.
Keywords: Dimorphic, Histoplasma capsulatum, immunocompromised
|How to cite this article:|
Sasikumari O, Anupama S. Disseminated histoplasmosis. J Acad Clin Microbiol 2017;19:109-11
| Introduction|| |
Histoplasmosis is a systemic granulomatous disease caused by three types of the dimorphic fungus, Histoplasma capsulatum var. capsulatum, H. capsulatum var. duboisii and H. capsulatum var. farciminosum. Infection is acquired by inhalation, and a vast majority of primary infections go unrecognised medically. It manifests initially as pulmonary histoplasmosis and may progress to disseminated infections. In human, it is an intracellular uninucleate organism involving cells of the reticuloendothelial system. It is a frequent cause of opportunistic infection among patients who are immunocompromised.
| Case Report|| |
A 63-year-old male presented with fever, weight loss and intermittent cough for 1 year, generalised pruritus for 2 months and an ulcerative lesion on the nose for 3 weeks. He was treated symptomatically in various peripheral hospitals. He was a known case of diabetes mellitus for 12 years and was on treatment with insulin. Finally, he was referred to Medical College, Thiruvananthapuram, Kerala, India, as a case of fever of unknown origin.
He had stayed in the state of Rajasthan, India, for 8 years and New Delhi for 2 years, where he worked as a manual labourer.
On examination, he was emaciated. There was a noduloulcerative lesion with crusting and scabbing on the nose which started as a raised lesion with pruritus [Figure 1]. He was treated with topical antifungal agents from various hospitals. The dermatology department had advised skin biopsy, but the patient was not willing.
Routine investigations were within normal limits (haemoglobin – 10 g %, total count – 9500/mm 3, differential count – P 76% L17% E 7%, ESR – 82 mm in 1st h, SGOT – 41 IU/L, SGPT – 52 IU/L, urea – 36 mg%, creatinine – 1.3 mg%, HIV – negative, chest X-ray PA view – normal, bronchoalveolar lavage study – normal, bone marrow trephine biopsy – normal, bone marrow AFB culture – culture negative for Mycobacterium tuberculosis).
Bone marrow specimen was sent to the Central Microbiology Laboratory of Government Medical College, Thiruvananthapuram, on 04.11.2015 for fungal culture.
The sample was inoculated on Sabouraud's Dextrose Agar (SDA) with actidione and without actidione, and these were incubated both at 37°C and at 22°C (room temperature).
After 2 week, SDA with actidione incubated at 22°C showed the following:
- Obverse: White cottony growth with fluffy texture [Figure 2]
- Reverse: No pigmentation
- The fungus was processed in a biological safety cabinet
- Microscopy: Wet film using lactophenol cotton blue showed the following finding [Figure 3] and [Figure 4]
- Hyphae: Thin, septate hyaline hyphae
- Conidia: Microconidia and macroconidia are seen
- Microconidia: Smooth-walled small conidia of 2–4 μm seen directly on the hyphae or short conidiophores
- Macroconidia: Large hyaline thick-walled conidia of 13–15 μm, spherical with tuberculate extensions on the wall seen directly on the hyphae or from short tubular conidiophores.
The fungus morphologically resembled Histoplasma species. Hence, it was inoculated on brain–heart infusion broth which was incubated at 37°C to demonstrate dimorphism. After two weeks of incubation, broth became turbid. Yeast forms were not satisfactorily demonstrated, so the fungus was sent to national culture collection of pathogenic fungi, PGI Chandigarh, for characterisation and identification. The fungus was identified as H. capsulatum var. capsulatum.
The patient was treated with Amphotericin B 1 mg/kg body weight for two weeks. Fever subsided on the second day of treatment. The patient was discharged against medical advice, and he was treated with oral itraconazole 200 mg twice daily to be taken for one year.
After 2 months, the patient was brought again to medical college with fever and chills. He had discontinued the treatment, and he died in Jan 2016. No other repeat samples were taken from the patient for any kind of investigations
| Discussion|| |
H. capsulatum is a thermally dimorphic fungus which appears as mycelial form at 22°C and yeast form at 37°C. Inside the body, it is an intracellular uninucleate organism which affects the reticuloendothelial cells.
H. capsulatum has been isolated from soil with high nitrogen content, especially related to dropping of starling, chickens and bats. The infection takes place by inhalation of microconidia, which are the infective forms.
Histoplasmosis commonly manifests clinical features such as high persistent fever, fatigue and weight loss resembling disseminated tuberculosis. It has been considered as an AIDS-defining illness. The disease can become chronic, progressive and even fatal.
In Kerala, several cases of histoplasmosis are diagnosed presenting as a noduloulcerative growth on the hard palate. Tender ulcerated lesions may be seen on the soft palate., In this case, the patient presented with fever and noduloulcerative lesion on the nose. Disseminated histoplasmosis is rarely suspected in India. Awareness of this infection is important for adequate treatment and to differentiate it from more common diseases such as tuberculosis, leishmaniasis and malignancy.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Remadevi S. Histoplasmosis: An emerging infection. J Acad Clin Microbiol 2014;16:70-6. [Full text]
Panja G, Sen S. A unique case of histoplasmosis. J Indian Med Assoc 1954;23:257-8.
Sane SY, Patel MG, Patel BM, Kokal K. Disseminated histoplasmosis (a case report). J Postgrad Med 1983;29:270-3.
] [Full text]
[Figure 1], [Figure 2], [Figure 3], [Figure 4]