Histoplasmosis is a disease with many names. It can be known as “caver’s disease”, “spelunker’s lung”, “cave disease”, “Darling’s disease”, “reticuloendotheliosis”, or “Ohio Valley disease”. It can cause a variation of symptoms due to an infection by the fungus, Histoplasma capsulatum. When other organs besides the lungs are affected, it is known as disseminated histoplasmosis. If left untreated, this can be fatal. It is a common disease seen among patients with acquired immune deficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV) infection. In normal individuals who are not immunosuppressed or immunocompromised, a past infection can lead to partial protection.
Histoplasma capsulatum is often found in soil where there is decaying bird droppings or guano. It has been found in caves, bird roosts (especially starlings), poultry house litter, and areas harboring bats. The disruption of soil due to construction or excavation may release the infectious elements into the air which are then inhaled and settle into the lungs causing pathology. The disease is not contagious and is only contracted through the inhalation of spores. Since there is a wide spectrum of symptoms, the diagnosis can be difficult.
Tests include the identification of the fungus from blood, organs, or sputum; detection of antigens in the urine samples or blood; detection of Histoplasma antibodies in the blood; and Histoplasma skin tests. The disease resolves without treatment in most immunocompetent individuals.
Histoplasmosis Symptom #1: Fever
Fever is also known as a febrile response or pyrexia. It can be defined as an excessive increase in body temperature due to a new higher set point of body temperature. This leads to a feeling of coldness (chills) and muscle contractions (rigors) in an effort to produce more heat. It can be caused by various conditions such as parasitic, bacterial, viral, or fungal infections. Non-infectious causes include deep vein thrombosis, cancer, side effect of medication, and vasculitis.