Coccidioides Immitis Spherule
Coccidioides Immitis Spherule (Spherusol®) is a diagnostic skin test antigen used to detect delayed-type hypersensitivity to Coccidioides immitis, the fungus causing coccidioidomycosis (Valley fever). It is specifically indicated for individuals with a history of pulmonary coccidioidomycosis to evaluate their cellular immune response to the pathogen. A positive DTH reaction indicates prior exposure and immune sensitization to C. immitis.
A diagnostic skin test antigen that detects cellular immune response to C. immitis in patients with a history of pulmonary coccidioidomycosis.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- RxNorm
- 1549330
- Generic
- Coccidioides Immitis Spherule
- Class
- unclassified
- Brands
- Spherusol
- Availability
- rx
- Pregnancy
- C
- Lactation
- caution
- Routes
- —
- Forms
- solution
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Used as a diagnostic tool in individuals with documented or suspected history of pulmonary coccidioidomycosis to assess for delayed-type hypersensitivity (DTH) response to Coccidioides immitis. A positive reaction may indicate immunological sensitization to the fungus.
When injected intradermally, Spherusol® stimulates a localized cellular immune response in sensitized individuals, manifesting as a delayed-type hypersensitivity (DTH) reaction at the injection site within 24-72 hours. This response indicates the presence of C. immitis-specific T-cell mediated immunity.
This is a diagnostic agent, not a therapeutic medication. Interpretation should consider the patient's clinical history and radiographic findings. Skin testing should be performed by healthcare professionals familiar with delayed-type hypersensitivity testing. Results should be correlated with clinical presentation, as false positives or negatives may occur.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy