SYSTEMIC MYCOSES:

Systemic mycoses include a group of fungal infections that affect the internal organs. The fungi have the ability to enter the body through the lungs, gut, paranasal sinuses, or the skin. Most infections tend to originate in the respiratory tract and then spread through the bloodstream to multiple organs including the skin, often causing multiple organs to fail and eventually resulting in the death of the patient.

The following diseases are caused by dimorphic fungi, the organism exist in two form (cold (20°C) = mold; heat (37°C) = yeast), except the coccidioidomycosis, which is a spherule in tissue, not yeast. (Le, Bhushan, & Grimm, 2011). Systemic mycoses can mimic TB (granuloma formation) but unlike TB, have no person to person transmission.

Histoplasmosis: caused by histomaplasma capsulatum, present like pneumonia, it is endemic from Mississippi and Ohio River valleys. Most individuals with histoplasmosis are asymptomatic. Those who develop clinical manifestations are usually immunocompromised or are exposed to a high quantity of inoculum (Fayyaz, 2011). Histoplasma species may remain latent in healed granulomas and recur, resulting in cell-mediated immunity impairment.

Blastomycosis: caused by Blastomyces dermatitidis. Causes inflammatory lung disease and disseminate to skin and bone, form granulomatous nodules. It is endemic from State east of Mississippi and Central America.(Le, 2011).

It is a common infection among dogs in endemic areas. It may serve as an indicator of human disease because of the shared environment. Blastomycosis is reported in other animals, including the horse, cow, cat, bat, and lion. (Varkey, 2011).

 Coccidioidomycosis: caused by Coccidioides immitis, it is a soil fungus endemic from Southwestern United State, California, and by Coccidioides pasadasii, which is endemic from certain arid to semiarid areas of the Southwestern United States (Hospenthal, 2011), produce pneumonia and meningitis, also it can disseminate to bone and skin. According to Le, Bhushan and Grimm (2011) the number of case increase after the earthquakes.

Paracoccidioidomycosis: caused by Paracoccidioides brasiliensis, it is endemic from South and Central America; formerly know as South American Blastomycosis and Lutz-Splendore-Almeida disease, most commonly manifests as a chronic progressive systemic mycosis in men. Pneumonia following dissemination is the most common presentation, also involves the mucous membranes, skin, and lymph nodes (Brazao-Silva, et al., 2011), the disease usually progresses to fatality unless effectively treated.

TREATMENT: The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Local infection = fluconazole (diflucan) or ketoconazole.

 Systemic infection = amphotericin B.

Other options:

            Itraconazole is the drug of choice in mild-to-moderate pulmonary blastomycosis (Varkey, 2011). The appropriate dose is 200 mg/d for 6 months. The value of a higher dose is uncertain. Gastric acidity is required for absorption of itraconazole. Itraconazole provides the ease of oral administration, low toxicity, and high efficacy. Can be used as substitute for ketoconazole (Fayyaz, 2011) , also can be used for mildly symptomatic or prolonged acute pulmonary histoplasmosis.

Bibliography

Brazao-Silva, M., Andrade, M., Franco, T., Ribeiro, R., Silva Wdos, S., & Faria, G. (2011, Jul; 54 (4): e189-95). medscape.com. Retrieved from Paracoccidioidomycosis: a series of 66 patients with oral lesions from an endemic area. Mycoses: http://reference.medscape.com/medline/abstract/20406390

Fayyaz, J. (2011, Aug 26). medscape. Retrieved from Histoplasmosis: http://emedicine.medscape.com/article/299054-overview

Hospenthal, D. R. (2011, Dec 8). medscape.com. Retrieved from Coccidioidomycosis: http://emedicine.medscape.com/article/215978-overview

Le, T., Bhushan, V., & Grimm, L. (2011). Fisrt AID for the USMLE step 1. usa: McGraw Hill.

Varkey, B. (2011, Feb 8). medscape. Retrieved from Blastomycosis: http://emedicine.medscape.com/article/296870-overview