210 An Introduction to Medical Mycology 



row to the surface of the skin, and fistulas may form. When the central 

 nervous system is invaded, evidence of meningitis is usually present. The 

 various internal organs, such as the liver, the kidneys, the spleen and the 

 heart, may all be invaded by C. immitis with widespread involvement. The 

 intestines have never shown lesions of Coccidioides (Ophuls). 



(d) Histology.— Biopsy material for diagnosis may be either a section of 

 skin or an accessible lymph node. The histologic findings are similar in both 

 tissues. An early lesion, before liquefaction, shows an intense cellular reac- 

 tion surrounding the organism. The infiltrate contains lymphocytes and epi- 

 thelioid cells, and one or more giant cells are usually present; often a giant 

 cell contains a parasite. The subsequent picture varies considerably with 

 the type of lesion and the duration of the disease. Frequently polymor- 

 phonuclear cells invade the area, and the nodule, which becomes an abscess, 

 is destroyed by progressive suppuration. A wall of plasma cells, lympho- 

 cytes and connective tissue separates the pus from the deeper layers. The 

 micro-organism can usually be demonstrated; endospores are nearly always 

 present and because of them it can hardly be confused with any other 

 fungus. The formation of new blood vessels and of fibrous tissue eventually 

 occurs. 



(e) Immune reactions.— The reaction to coccidioidin is considered to 

 be specific, denoting infection with C. immitis. One should employ needles 

 and syringes which have not been used for similar tests with other antigens. 

 Since the reaction may remain long after an infection has apparently dis- 

 appeared, the test is not necessarily diagnostic of a given infective process. 

 As with similar allergic reactions, the interpretation must be correlated 

 with the clinical and laboratory findings. Using an antigen supplied by 

 Dickson, we studied the intracutaneous test in New York. In 400 patients 

 with no evidence of coccidioidomycosis a negative reaction was invariable. 



The presence of agglutinins, precipitins or complement-fixing bodies in 

 the blood of infected persons has not been entirely established. Cooke 

 noted positive precipitation reactions, and Cooke and Davis obtained a 

 positive complement fixation reaction. Dilutions of mycelial suspensions 

 were very low, i.e., relatively large amounts of suspension were required. 



(f) Differential diagnosis.— Demonstration of the organism in pus 

 removed from a lesion in the skin, from sputum, from the spinal fluid or 

 from other sites is usually readily accomplished, and cultures are grown 

 with equal facility. Contamination may complicate the technic. When 

 some difficulty is encountered, animal inoculation may prove of value. 

 The disease should be particularly suspected in a man presenting a granu- 

 lomatous lesion (usually soft) who has lived or is living in California. The 

 differentiation from tuberculosis on clinical grounds mav be difficult. The 



