What Is Valley Fever?


Valley fever, also known as coccidioidomycosis, is a fungal infection caused by inhaling spores of the soil fungus Coccidioides.  The infection is common in dry areas, especially in the southwestern United States, Mexico, and parts of Central and South America.1  While Valley Fever might appear asymptomatically at times, its symptoms can range from mild flu-like symptoms to severe respiratory issues - it presents itself as a pulmonary infection.  In some situations, the fungal infection might spread to other regions of the body.Valley fever is not contagious to others because it is obtained by the inhalation of fungus spores found in the environment.   The severity of the infection varies, with many cases clearing up on their own, but in other situations, medical attention is required.

Significance of understanding valley fever

Understanding Valley Fever is important for a multitude of reasons:

Awareness of endemic areas 

Valley Fever is common in certain geographical settings, most notably dry ones. You must be aware if you are entering these endemic areas to take preventive actions and recognise symptoms early. 3

Preventative measures

Being aware of the risk factors and the transmission of Valley Fever empowers us to take preventive measures, including wearing dust masks with N95 respirators and wearing protective clothing to limit exposure.

High-risk population 

Certain groups, such as those with compromised immune systems or pregnant women, may be at a higher risk of serious consequences. 

Individuals in these groups should be especially cautious about implementing measures to avoid exposure to Valley Fever. 4

Reduce chances of misdiagnosis

Valley Fever has symptoms similar to the common cold, making proper diagnosis difficult. It is critical to be aware of this fungal infection to avoid misdiagnosis and associated repercussions. Recognising Valley Fever's distinguishing traits allows for early care, lowering the chance of catastrophic results.

Origin and fungal source - coccidioides

Valley Fever is caused by a soil-dwelling fungus called Coccidioides. This fungus causes Coccidioidomycosis, the scientific name for Valley Fever.  Coccidioides is found only in areas that are arid or semi-arid, primarily in the southwestern United States, Mexico, and sections of Central and South America.  Coccidioides' life cycle begins in its natural habitat as mould in the soil.   The fungus spores go airborne when the soil is disturbed, such as during construction or farming, or natural phenomena such as dust storms or earthquakes.  When inhaled, the spores can change into a more aggressive form, resulting in disease development.

Geographic distribution

Valley Fever is endemic in the following areas5

  1. Southwest of the United States: particularly places such as Arizona, California, New Mexico, and Texas.
  2. Mexico: Northern Mexico, which has a dry climate similar to the southwestern United States, is likewise endemic for Valley Fever. Sonora, Chihuahua, and Baja California are recognised to have higher illness incidences.
  3. South and Central America: valley fever has been documented in some places of Central and South America, including Argentina and Venezuela.


Airborne Transmission: Valley Fever is caught by breathing in fungal spores found in dust or soil particles. Construction, agricultural labour, and even natural events like dust storms can increase the probability of exposure.6

Human-human: Valley Fever is not passed from person to person. Valley Fever is an environmental fungal infection, and those who have it do not pose a direct hazard to others.6

Animal-human: Although Valley fever can infect domestic and wild animals, the fungus is not spread between animals and humans.6

Risk factors

Valley Fever risk factors include

  • Living in or travelling to endemic areas 
  • Engaging in soil-disturbing activities (e.g., construction, agriculture)
  • Being elderly
  • Having compromised immune systems 
  • and pregnancy (particularly in the third trimester)7

Symptoms and forms

Acute and chronic manifestations

Understanding the difference between acute and chronic forms of infection is critical to receiving proper management and therapy based on the severity and duration of the illness.

Acute Form: 

  • Valley Fever's acute form is the most common presentation, which is characterised by flu-like symptoms such as:8
    • Fever
    • Cough
    • Chest pain
    • Lethargy
    • Headache
    • Muscular aches, and 
    • Joint pain
  • In many cases, the immune system handles the infection efficiently, resulting in a self-limiting illness and recovery without needing specialist antifungal treatment.
  • Nonetheless, certain cases, particularly in people with weakened immune systems, pregnant women, or elderly people, might progress to severe pneumonia, necessitating immediate medical attention and specific interventions.

Chronic Form:

  • When the infection persists beyond the acute phase, a less common but more severe chronic  Valley Fever develops, resulting in persistent and debilitating symptoms such as:9
    • Cough that persists
    • Hemoptysis (coughing up blood)
    • Weight loss
    • Chest discomfort
    • Dyspnea (shortness of breath)
  • This chronic variation can cause the formation of lung nodules or cavities, and in certain cases, the infection can spread to other parts of the body, such as the skin, bones, joints, or even the central nervous system.
  • Chronic Valley Fever often requires extended and specialised antifungal therapy, and the condition can have a substantial influence on the overall health of those affected.

Complications and severity

Understanding the potential complications and severity of Valley Fever is critical for healthcare providers to offer proper medical care and for you to recognise the significance of obtaining immediate medical help, particularly if symptoms persist or worsen. Early detection and intervention can have a substantial impact on the outcome and lower the chance of serious complications. If the fungus is not treated properly or is recognised in an immunocompromised host, it can spread to the lungs, brain, and meninges, causing respiratory failure, sepsis, shock, and even death.10

Such complications include: 

  1. Disseminated Valley Fever
    • The infection can spread beyond the lungs to other areas of the body in certain cases, resulting in disseminated Valley Fever. 
    • This can affect the skin, bones, joints, or the nervous system. 
    • Disseminated Valley Fever is characterised by more severe and long-lasting symptoms.
    • Cases of disseminated valley fever have been reported due to insufficient treatment duration, although other variables may have contributed to the disease's extended course.11 
  1. Coccidioidomycosis meningitis (CM)
    • One of the more severe complications is when it spreads to the meninges, resulting in coccidioidomycosis meningitis. 
    • CM occurs when the protective membranes around the brain and spinal cord become inflamed. 
    • CM can result in severe headaches, stiffness in the neck, and neurological problems.
    • CM is particularly concerning for immunocompromised individuals, as their weakened defence mechanisms make them more susceptible to severe complications.10 
  1. Skin lesions
    • The spread of the infection to the skin may result in the formation of painful, ulcerating skin sores.
    • The skin is frequently included among the organs most usually impacted.12
  1. Pregnancy complications
    • Pregnant women with Valley Fever are at a higher risk of problems, such as early birth and illness dissemination to the unborn child.
    • The risk of dissemination grows as the weeks of pregnancy go on, with the third trimester and early postpartum period being the most dangerous.12
    • Based on reported cases, there is an indication that appropriate treatment increases the likelihood of a positive pregnancy outcome in subsequent pregnancies.

Diagnosis and testing

Clinical assessment

Valley Fever clinical assessment includes reviewing the patient's history for geographic and work-related exposures, examining symptoms and performing a thorough physical examination, using diagnostic techniques such as serology and imaging, and taking risk factors into account for an in-depth diagnosis and management plan.12

Laboratory tests

Valley Fever laboratory tests include:12

  • Serologic tests that identify specific antibodies, such as immunodiffusion and enzyme immunoassays 
  • Fungal cultures from sputum (thick mucus made in the lungs)  or tissue samples, as well as blood tests such as complete blood count, ESR, and CRP, aid in the diagnosis process 

Imaging studies

Imaging studies, such as chest X-rays and CT scans, provide crucial information about pulmonary and extrapulmonary involvement, allowing for a more thorough diagnosis.12 

Treatment and management

Antifungal medications

Azole antifungal treatments for Valley Fever include fluconazole and itraconazole, with amphotericin B reserved for severe infections.  Treatment duration varies, and constant monitoring is required to measure effectiveness as well as minimise potential side effects.   Patient education on drug adherence, as well as regular follow-up sessions, are critical components of effective antifungal therapy.9

Symptom management

Valley Fever symptom therapy entails addressing specific signs and symptoms, such as utilising antipyretics for a high temperature, analgesics for pain alleviation, and cough suppressant medications if necessary.9

Hydration and rest are critical, and in severe situations, medical measures such as oxygen supplementation or pain relievers may be required.   Close symptom monitoring, quick medical attention, and compliance with antifungal therapy all contribute to good symptom management and total recovery.9

Living with valley fever

Coping strategies

Living with Valley Fever necessitates an all-encompassing strategy that takes into account physical, mental, and lifestyle factors.   Developing a solid support network, remaining up-to-date, and actively taking responsibility for your healthcare all lead to a healthier and more adaptable way of life.10

Support for patients and families

If you require extra assistance, make contact with healthcare experts, patient advocacy groups, or respiratory health organisations.10


To summarise, the key to successfully reducing Valley Fever is early detection and prompt treatment. Recognising symptoms and seeking medical attention early allows for the timely beginning of antifungal therapy, lowering the risk of consequences. To raise awareness, promote early testing, and provide a holistic, supportive approach to managing this fungal illness, healthcare professionals, communities, and individuals must work together. Early intervention is critical to improving health outcomes and boosting the well-being of Valley Fever patients. 


  1. Is Valley Fever the same as Rift Valley fever? 

No. Valley Fever is a fungal infection produced by inhaling spores, whereas Rift Valley Fever is a viral infection spread mostly by mosquitoes or contact with infected livestock. They are separate diseases with independent causal agents and routes of transmission.

  1. How do you differentiate a common cold from valley fever? 

Due to overlapping symptoms, distinguishing between a typical cold and Valley Fever can be difficult. However, characteristics such as geographic location (Valley Fever is more common in arid locations), environmental exposure to dust and soil, and the duration and intensity of symptoms can all help differentiate the disease.


  1. Ashraf N, Kubat RC, Poplin V, Adenis AA, Denning DW, Wright L, et al. Re-drawing the maps for endemic mycoses. Mycopathologia [Internet]. 2020 Oct [cited 2024 Mar 22];185(5):843–65. Available from: https://link.springer.com/10.1007/s11046-020-00431-2 
  2. Gorris ME, Treseder KK, Zender CS, Randerson JT. Expansion of coccidioidomycosis endemic regions in the united states in response to climate change. GeoHealth [Internet]. 2019 Oct [cited 2024 Mar 22];3(10):308–27. Available from: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GH000209
  3. Crum NF. Coccidioidomycosis: a contemporary review. Infect Dis Ther [Internet]. 2022 Apr [cited 2024 Mar 22];11(2):713–42. Available from: https://link.springer.com/10.1007/s40121-022-00606-y
  4. Akram SM, Koirala J. Coccidioidomycosis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 [cited 2024 Mar 22]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK448161/
  5. Ghantarchyan H, Oganesian B, Gayed MM, Maknouni B, Hasan M. A rare case of coccidioidomycosis meningitis. J Med Cases [Internet]. 2023 Mar [cited 2024 Mar 22];14(3):81–7. Available from: http://www.journalmc.org/index.php/JMC/article/view/4040
  6. Dev A, Janysek D, Gnecco J, Haghayeghi K. Disseminated coccidioidomycosis following insufficient treatment at initial presentation: case report. Journal of Investigative Medicine High Impact Case Reports [Internet]. 2020 Jan [cited 2024 Mar 22];8:232470962094931. Available from: http://journals.sagepub.com/doi/10.1177/2324709620949315
  7. Garcia Garcia SC, Salas Alanis JC, Flores MG, Gonzalez Gonzalez SE, Vera Cabrera L, Ocampo Candiani J. Coccidioidomycosis and the skin: a comprehensive review. An Bras Dermatol [Internet]. 2015 Oct [cited 2024 Mar 22];90(5):610–9. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0365-05962015000500610&lng=en&tlng=en
  8. Labuschagne H, Burns C, Martinez S, Carrillo M, Waggoner M, Schwanninger I, et al. Coccidioidomycosis in pregnancy: Case report and literature review of associated placental lesions. Case Reports in Women’s Health [Internet]. 2016 Oct [cited 2024 Mar 22];12:5–10. Available from: https://linkinghub.elsevier.com/retrieve/pii/S2214911216300236
  9. Blair JE, Mendoza N, Force S, Chang YHH, Grys TE. The clinical specificity of the enzyme immunoassay test for coccidioidomycosis varies according to the reason for its performance. Clin Vaccine Immunol [Internet]. 2013 Jan [cited 2024 Mar 22];20(1):95–8. Available from: https://journals.asm.org/doi/10.1128/CVI.00531-12
  10. Crete RN, Gallmann W, Karis JP, Ross J. Spinal coccidioidomycosis: MR imaging findings in 41 patients. AJNR Am J Neuroradiol [Internet]. 2018 Nov [cited 2024 Mar 22];39(11):2148–53. Available from: http://www.ajnr.org/lookup/doi/10.3174/ajnr.A5818
  11. Ampel NM. The treatment of coccidioidomycosis. Rev Inst Med trop S Paulo [Internet]. 2015 Sep [cited 2024 Mar 22];57(suppl 19):51–6. Available from: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0036-46652015000800051&lng=en&tlng=en
  12. Aronoff DM, Neilson EG. Antipyretics: mechanisms of action and clinical use in fever suppression. The American Journal of Medicine [Internet]. 2001 Sep [cited 2024 Mar 22];111(4):304–15. Available from: https://linkinghub.elsevier.com/retrieve/pii/S0002934301008348
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

Get our health newsletter

Get daily health and wellness advice from our medical team.
Your privacy is important to us. Any information you provide to this website may be placed by us on our servers. If you do not agree do not provide the information.
my.klarity.health presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
Klarity / Managed Self Ltd
Alum House
5 Alum Chine Road
Westbourne Bournemouth BH4 8DT
VAT Number: 362 5758 74
Company Number: 10696687

Phone Number:

 +44 20 3239 9818