Histoplasmosis can also be diagnosed by a test for antibodies against Histoplasma in the blood. Histoplasma skin tests indicate whether persons have been exposed, but do not indicate whether they have the disease. Formal histoplasmosis diagnoses are often confirmed only by culturing the fungus directly. Sabouraud agar is one agar growth medium on which the fungus can be cultured. Cutaneous manifestations of disseminated disease are diverse and often present as a nondescript rash with systemic complaints. Diagnosis is best established by urine antigen testing, as blood cultures may take up to 6 weeks for diagnostic growth to occur and serum antigen testing often comes back with a false negative before 4 weeks of disseminated infection. Types
Histoplasmosis may be divided into these types:: 316–317 
Primary pulmonary histoplasmosis
Progressive disseminated histoplasmosis
Primary cutaneous histoplasmosis
African histoplasmosis

Prevention
Testing or decontaminating most sites that may be contaminated with H. capsulatum is impractical, but the sources below list environments where histoplasmosis is common, and precautions to reduce a persons risk of exposure, in the three parts of the world where the disease is prevalent. Precautions common to all geographical locations would be to avoid accumulations of bird or bat droppings.The US National Institute for Occupational Safety and Health  provides information on work practices and personal protective equipment that may reduce the risk of infection.A review paper includes information on locations in which Histoplasma has been found in Africa (in chicken runs, on bats, in the caves bats inhabit, and in soil), and a thorough reference list including English, French, and Spanish language references.
Chronic histoplasmosis cases can  resemble tuberculosis; disseminated histoplasmosis affects multiple organ systems and is fatal unless treated.While histoplasmosis is the most common cause of mediastinitis, this remains a relatively rare disease. Severe infections can cause hepatosplenomegaly, lymphadenopathy, and adrenal enlargement. Lesions often left calcification nodules as they are healed.Presumed ocular histoplasmosis syndrome  causes chorioretinitis, where  the choroid and retina of the eyes are scarred, resulting in a loss of vision not unlike macular degeneration. Despite its name, the relationship to Histoplasma is controversial. Distinct from POHS, acute ocular histoplasmosis may rarely occur in immunodeficiency. Complications
In absence of proper treatment and especially in immunocompromised individuals, complications can arise. These include recurrent pneumonia, respiratory failure, fibrosing mediastinitis, superior vena cava syndrome, pulmonary vessel obstruction, and progressive fibrosis of lymph nodes. Fibrosing mediastinitis is a serious complication and can be fatal. Smokers with structural lung disease have higher probability of developing chronic cavitary histoplasmosis.After healing of lesions, hard, calcified lymph nodes can erode the walls of the airway, causing hemoptysis. Mechanisms
H. capsulatum grows in soil and material contaminated with bird or bat droppings (guano). The fungus has been found in poultry-house litter, caves, areas harboring bats, and bird roosts (particularly those of starlings). The fungus is thermally dimorphic; in the environment, it grows as a brownish mycelium, and at body temperature (37°C in humans), it morphs into a yeast. Histoplasmosis is not contagious but is contracted by inhalation of the spores from disturbed soil or guano. The inoculum is represented principally by microconidia.