What are the signs and symptoms of valley fever and its treatment options?

Signs and Symptoms of Valley Fever (Coccidioidomycosis)

Valley fever presents most commonly as a self-limited acute or subacute community-acquired pneumonia that becomes evident 1-3 weeks after infection with Coccidioides fungi. 1

Common Clinical Manifestations

• The most frequently reported symptoms include fever, fatigue, chills, and myalgia 2
• Severe, debilitating headaches are common and may be retroorbital with photophobia, sometimes misdiagnosed as migraines or dental issues 2
• Respiratory symptoms include pneumonia with cough (often nonproductive in 50% of cases) and chest pain 2, 3
• A classic triad known as "desert rheumatism" includes fever, erythema nodosum (skin rash), and arthralgia 4
• Approximately 60% of infections are asymptomatic, while about one-third develop pulmonary illness 5

Disease Course and Progression

• Symptoms typically appear 1-3 weeks after exposure to the fungal spores 1
• Fever typically lasts a median of 10 days in untreated patients (range: 5-57 days) and usually resolves within 72 hours of appropriate treatment 2
• Systemic symptoms (fever, night sweats, weight loss) typically improve first, followed by respiratory symptoms, with fatigue often being the most persistent symptom 2
• In immunocompetent individuals, most infections are self-limited and resolve spontaneously without specific antifungal therapy 3, 6

Complications and Severe Presentations

• Disseminated disease occurs in 0.5-2% of cases, affecting extrapulmonary sites such as skin, bones/joints, and the central nervous system 5
• Risk factors for dissemination include:
  • Cellular immunodeficiencies (transplant recipients, HIV) 5
  • Pregnancy 5
  • Non-Caucasian race (especially African Americans and Filipinos) 5
• Persistent pulmonary cavities may develop and can be symptomatic 6

Diagnostic Considerations

• Serologic testing is the primary diagnostic method, including both IgM and IgG antibodies against coccidioidal antigens 3
• For suspected cases, comparative testing of acute and convalescent serum samples (6 weeks apart) is recommended to detect seroconversion 3
• Nucleic acid detection via PCR can be useful in early disease (first 2 weeks) before antibody response develops 3
• Erythrocyte sedimentation rate is often elevated and can be used to monitor improvement 2

Treatment Approach

• For immunocompetent patients with mild to moderate symptoms, antifungal therapy is generally not required 3, 6
• Antifungal treatment is indicated for:
  • Severe primary pulmonary disease with significant symptoms 3, 6
  • Patients with risk factors for dissemination 3
  • Disseminated disease 6
• When treatment is needed, fluconazole is the standard first-line drug (400 mg daily for mild-moderate disease, 800 mg daily for severe disease) 3, 6
• Itraconazole (200 mg twice daily) may be more effective for skeletal infections 3, 6
• Liposomal amphotericin B is recommended for critically ill patients, rapidly progressive disease, or those who fail to respond to azole therapy 3, 6

Follow-up and Monitoring

• Regular medical follow-up is essential for all patients with valley fever 2
• Patients should be educated about the disease course and when to seek further medical attention 2, 3
• Laboratory studies (erythrocyte sedimentation rate, antibody titers) and chest radiographs should be monitored periodically to assess disease resolution 2

Common Pitfalls

• Misdiagnosis as bacterial pneumonia or other respiratory infections due to similar presentation 2
• Unnecessary antifungal treatment in immunocompetent patients with mild disease, which can lead to adverse effects without clinical benefit 6
• Failure to consider valley fever in patients with compatible symptoms who have lived in or traveled to endemic regions 1
• Delayed diagnosis due to lack of awareness of the expanding geographic distribution of Coccidioides 5