Year : 2021 Month : December Volume : 10 Issue : 45 Page : 4047-4049,

Disseminated Histoplasmosis in an Immunocompromised Individual

Altous F.1, Rupak Protim Patir2, Angelia L. Khawbung3

1, 2, 3 Department of Medicine, Fakhruddin Ali Ahmed Medical College and Hospital, Barpeta, Assam, India.

CORRESPONDING AUTHOR

Dr. Rupak Protim Patir, Senior Resident, Department of Medicine, Fakhruddin Ali Ahmed Medical College and Hospital, Barpeta-781301, Assam, India.
Email : rpatir333@gmail.com

INTRODUCTION

Histoplasma capsulatum is a dimorphic fungus usually found in the few regions of West Bengal and Assam, the Gangetic Plains, western parts of India, and sporadically from southern and few northern Indian states.1 Humans are infected by inhalation of microconidia and mycelial fragments of H. capsulatum.2 It commonly infects immunocompromised patients (HIV/AIDS, transplant patients and patients receiving immunosuppressive agents). In immunocompromised patients, it presents as nonspecific symptoms such as fever of unknown origin, weight loss, oral and aphthous ulcers, lymphadenopathy and hepatosplenomegaly.3 Here, we are reporting a case of disseminated histoplasmosis in an immunocompromised patient.

PRESENTATION OF CASE

A 47-year-old male, a newly diagnosed immunocompromised patient had presented with low-grade fever, weight loss, cough, decreased appetite, loose stool, worsening of breathlessness for 1 year. He was taking antitubercular treatment for 6 months before (radiologically diagnosed) and later discontinued the medication. He was afebrile (Temp 99 , pulse 114/min regular), hypotensive 90/60, respiratory rate of 23/min, pallor and malnourished with wasting. On laboratory investigation revealed pancytopenia with Hb-4.7 g/dl, TC-2070 cells/mm3 (N-54.5, L-43.5, E-0.5, M-1), MCV- 58, MCH – 18.6, MCHC - 32, platelet count – 90,000/mm3, RBC – 2.47 lakhs/mm3, reticulocyte count – 3.5 %  in complete blood count. Liver function test abnormal (Total bilirubin 6 mg/dl, unconjugated bilirubin 4.3 mg/dl, AST-98 IU/L, ALT – 28 IU/L, AlkP – 217 IU/L, S. Albumin – 1.5 g/dl, Globulin – 3.2 g/dl ). Thyroid function test, renal and electrolyte parameters were normal, S. Iron – 25 mg/dl, S. Ferritin - 528 mg/dl, TIBC – 183 mg/dl, ESR – 45. HRCT thorax revealed multiple tiny opacities distributed over bilateral lung fields f/s/o milliary tuberculosis. USG revealed acute calculous cholecystitis. Sputum AFB and Gene Xpert were negative. Bone marrow aspiration cytology was done and a bone marrow smear with Giemsa stain showed intracellular yeast cells. He was treated for progressive disseminated histoplasmosis.

 

 

 

DISCUSSION

Disseminated histoplasmosis is also known as Darling’s Disease and the causative organism is Histoplasma capsulatum first described by Samuel Darling which is a dimorphic fungus that exists in the environment as mould form and the tissues as a yeast form at 35  to 37 .3,4 Systemic histoplasmosis is usually acquired via inhalation of microconidia or hyphal elements found in contaminated soil with bird and bat droppings which would lead to primary infection such as acute or chronic (cavitary) pulmonary histoplasmosis or as acute, subacute, or chronic progressive disseminated histoplasmosis in most common and classic forms. Often it is misdiagnosed as tuberculosis.5 The infection usually spreads via a haematogenous route from the pulmonary site to the lymph nodes and various organs. In an immunocompetent individual, histoplasma infection is usually mild and self-limiting and in the case of immunocompromised individuals, the infection can be severe and disseminated to various organs especially with CD4 count < 200 cells per microlitre.6 Our patient had pulmonary histoplasmosis with bone marrow involvement suggestive of chronic progressive disseminated histoplasmosis. The patient was taking antitubercular drugs for suspected miliary tuberculosis without any benefit and the patient expired during treatment for histoplasmosis.

In chronic disseminated histoplasmosis that occurs via pulmonary infection, oral ulcers and vegetative plaques are common in an immunocompetent patient and dissemination may occur to the liver, spleen, bone marrow and other organs. In 70-90 % of cases, there is a gastrointestinal involvement and rarely adrenal involvement leading to adrenal insufficiency. Diagnosis is usually a suspicion from tissue specimen or aspirate cytology from the lymph node, bone marrow, or organ involved showing an intracellular yeast form especially in sections stained with Giemsa stain or PAS (Periodic acid Schiff) or Gomori methenamine silver stain. Culture in Sabouraud’s dextrose agar is confirmatory. Antibodies in serum can be detected by CFT and an immunodiffusion test can be taken as supportive evidence.1

For acute and chronic cavitary histoplasmosis, initial treatment usually starts with liposomal amphotericin B for 1-2 weeks followed by itraconazole 200 mg twice daily, continuous therapy for 12 months is a must.7 Monitoring of renal and hepatic function is a must. Our patient was initially started with liposomal amphotericin B 150 mg once daily (3mg/kg body weight) followed by itraconazole 200 mg twice daily. Highly active antiretroviral therapy (HAART) was also initiated concomitantly and during treatment, the patient expired. In immunocompromised individuals, itraconazole prophylaxis for life is advised if CD4 count <150 cells/mm3.7

CONCLUSIONS

In an immunocompromised patient with suspected pulmonary tuberculosis not responding to antitubercular therapy, systemic fungal infection such as histoplasmosis may be one of the differential diagnoses. However, early clinical suspicion, diagnosis and treatment can be a better part of patient care in modern medicine.

REFERENCES

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  3. Ling Q, Zhu W, Lu Q, et al. Disseminated histoplasmosis in an immunocompetent patient from an endemic area: a case report. Medicine (Baltimore) 2018;97(29):e11486.
  4. Doughan A. Disseminated histoplasmosis: case report and brief review. Travel Med Infect Di 2006;4(6):332-5.
  5. Ravindran S, Sobhanakumari K, Celine M, et al. African histoplasmosis: the first report of an indigenous case in India. Int J Dermatol 2015;54(4):451-5.
  6. Bonifaz A, Chang P, Moreno K. Disseminated histoplasmosis associated with acquired immunodeficiency syndrome: report of 23 cases. Clin Dermatol 2008;34:481-6.
  7. Wheat LJ, Freifeld AG, Kleiman MB, et al. Clinical practice guidelines for the management of patients with histoplasmosis: 2007 update by the Infectious Diseases Society of America. Clin Infect Dis 2007;45(7):807-25.

DISCLOSURE AND FUNDING

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Financial or other competing interests: None.

Disclosure forms provided by the authors are available with the full text of this article at jemds.com.

How to cite this article

Altous F, Patir RP, Khawbung AL. Disseminated histoplasmosis in an immunocompromised individual. J Evolution Med Dent Sci 2021;10(45):4047-4049, DOI: 10.14260/jemds/2021/818

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