Disseminated coccidioidomycosis is the severe form of the fungal disease in which there is a hematogenous spread of the infection from the lungs to the bone, joints, central nervous system (CNS), skin, and other organs in susceptible patients. The clinical picture is reflective of affected organs. The diagnosis is based on the presentation, physical exam, and appropriate studies.
Coccidioidomycosis can manifest in acute, chronic, and disseminated forms, of which the latter is the most severe . Overall, it is caused by airborne transmission of Coccidioides immitis spores. This endemic disease occurs in the southwestern region of the United States, Central America, and South America . Coccidioidomycosis is more common during the summer time and late fall . Risk factors for disseminated coccidioidomycosis include AIDS and other immunosuppressed states as a consequence of chronic steroid therapy, chemotherapy, diabetes, and lymphoma .
The majority of patients with coccidioidomycosis have a mild, self-limiting respiratory infection  . Symptomatic patients with a primary disease may exhibit fever, cough, dyspnea, malaise, arthralgia, chest pain, chills, weight loss, night sweats, and erythema nodosum . Susceptible patients are at risk for developing disseminated disease weeks or months following the initial infection, in which it spreads hematogenously from the lungs to the bone, joints, CNS, and skin . Extrapulmonary dissemination may occur even after a year of primary infection or following therapy. Those affected with disseminated infection report fever, dyspnea, weight loss, and night sweats.
Disseminated coccidioidomycosis can affect any organ. Musculoskeletal involvement results in lytic or sclerotic bone lesions and arthritis. Additionally, meningitis develops in nearly half of all patients with disseminated disease, which is associated with morbidity and mortality frequency . Specifically, meningitis is characterized by headaches, photophobia, and nuchal rigidity. Also, if present, increased intracranial pressure (ICP) leads to altered mental status and emesis. Patients may even develop cranial nerve palsies, seizures, and coma . Skin features in primary infection are commonly notable for diffuse maculopapular rashes which may evolve into erythema nodosum. Spread to the heart, which is rare, causes pericardial effusions and even tamponade .
Poor prognosis is associated with immunocompromised states and untreated individuals . Coccidioidal fungemia is a rare occurrence but involves spread to CNS, liver, and spleen. Acute respiratory distress syndrome (ARDS) and shock are other serious complications.
Patients could present with fever, splenomegaly, and lymphadenopathy. The clinical features will reflect affected organs or systems. Meningeal and other neurologic signs may be apparent. Also, skin infection may be remarkable for papules, plaques, or nodules. If present, pulmonary findings could include rales, rhonchi, and decreased breath sounds.
The diagnosis is based on the clinical manifestations, history including risk factors such as a recent travel to endemic areas and the patient's immunocompetence, physical exam, and the appropriate studies.
Laboratory studies should include complete blood count (CBC), which may be normal or significant for elevated lymphocytes, eosinophils, and monocytes. Additionally, there is an increase in erythrocyte sedimentation rate (ESR).
Diagnostic studies include serologic testing such as IgM and IgG antibodies as well as complement fixation techniques for IgG. Polymerase chain reaction (PCR), skin testing, blood cultures, and the urine antigen test are all helpful. Also, visualization of the fungus in body fluids such as blood, sputum, urine, or cerebrospinal fluid (CSF) is beneficial.
Patients with disseminated coccidioidomycosis could exhibit hilar and mediastinal adenopathy as well as the miliary pattern on chest X-ray. Other findings may also be present. Computed tomography (CT) scan reveals the morphology of the lesions more effectively .
Patients with suspected meningitis or other neurologic manifestations warrant assessment with CT and magnetic resonance imaging (MRI) of the brain, with the latter demonstrating better sensitivity for coccidioidal meningitis. Frequently observed abnormalities include basilar meningitis, vascular occlusion, and hydrocephalus.
Fluorodeoxyglucose positron emission tomography (FDG-PET) scans demonstrate diffuse intake reflective of disseminated disease and active infection. Also, bone scans are indicated in patients with osteomyelitis or suspected bone disease . MRI can also display affected bone and tissue.
Lumbar puncture is necessary for assessment of meningitis . Common findings in the CSF include lymphocytic and eosinophilic pleocytosis, increased protein, and low glucose levels. Complement-fixating antibodies in the CSF typically reveal elevated titers, which confirms the diagnosis of coccidioidal meningitis.