Coccidioidomycosis with Erythema Nodosum: A Case Report

Introduction

Also known as valley fever or desert rheumatism, coccidioidomycosis is a fungal disease commonly reported in the Western Hemisphere, especially the southwestern United States (mainly California, Arizona, and Texas), northern Mexico, and parts of Central and South America (Chen, Lee & Li, 2010). In the U.S., estimates indicate that 150,000 people in the southwestern region are infected every year (Garcia et al., 2015). As the disease is mainly concentrated in the southwestern U.S., its national prevalence remains unknown. The disease is commonly characterized by coughing, fever, shortness of breath, headaches, chest pain, night sweating, weight loss, and erythema nodosum (Garcia et al., 2015). This paper reports a case of coccidioidomycosis characterized by erythema nodosum.

A 31-year-old Asian male visited his primary care doctor's clinic complaining of cough and malaise for two months. He had been a construction worker in Fresno County, California, for eleven months, and his symptoms appeared after he began working there. He developed a temporary low-grade fever; however, he did not experience night sweats, hemoptysis, or headache. He was, however, positive for skin rashes characterized by painful red and brown bumps. The rashes were mostly on the lower limbs, with a few on his chest, arms, and back. Some rashes appeared as raised red lesions with blisters or eruptions resembling pimples. His previous medical record revealed no significant illnesses, and he did not smoke or use drugs.

Subjective

No significant diagnostic studies had previously been conducted on the patient. Nonetheless, inspection, palpation, percussion, and auscultation were performed to examine all systems associated with the patient's complaint. Percussion involved examining the condition of the thorax and abdomen, while auscultation was conducted using a stethoscope, with a particular focus on the circulatory and respiratory systems. Following percussion, no solid mass or hollow structure was detected in the patient's thorax or abdomen. Auscultation, however, revealed some unusual sounds in the chest.

Coccidioidomycosis occurs in a variety of clinical forms, ranging from mild fever to severe pulmonary or cutaneous manifestations. Primarily, the disease occurs in the lungs (Garcia et al., 2015). Indeed, the lungs comprise the most common site of infection. They are affected as a result of direct inhalation of arthroconidia, leading to pulmonary coccidioidomycosis. Pulmonary coccidioidomycosis is the most common form of the disease, with 60% of victims often being asymptomatic and the remaining 40% showing pulmonary symptoms one to three weeks following exposure to arthroconidia (Garcia et al., 2015). Common symptoms include fever, coughing, arthralgias, headache, intense fatigue, and chest pain, with symptoms in the acute phase persisting for more than three months (Chen, Lee & Li, 2010). Based on this, the unusual sounds detected in the patient's chest were likely an indication of pulmonary complications.

Objective

Inspection involved examining body features, skin color, and the frequency and depth of breaths during respiration. Physical examination did not reveal significant abnormalities. No abdominal discomfort, oral lesions, or conjunctivitis were observed. However, the patient had reddish rashes on his lower limbs, arms, chest, and back. On palpation, the rashes were tender and had blisters. Primary lung infection can spread to other body organs, notably the skin, the musculoskeletal system, and the nervous system — a condition known as disseminated coccidioidomycosis (Odio et al., 2017). Disseminated coccidioidomycosis affects up to 5% of coccidioidomycosis patients and often manifests clinically within 24 months of exposure (Garcia et al., 2015). The skin is the most common site of disseminated coccidioidomycosis. Cutaneous manifestations involve various forms, including erythema nodosum, erythema multiforme, Sweet's syndrome, and acute exanthema. Erythema nodosum is the most common form, manifesting one to three weeks following primary respiratory signs (Garcia et al., 2015). It is characterized by numerous erythematous, excruciating nodules commonly occurring in the lower extremities (Chen, Lee & Li, 2010). Therefore, coupled with fever and malaise, the rashes observed on the patient's skin were consistent with erythema nodosum.

The patient had a mild fever (38.1°C). Blood and metabolic analysis did not indicate any anomalies in normal white blood cell count, atypical lymphocytes, erythrocytes, serum creatinine, antibodies, or liver function. Blood culture tests also returned negative results for fungi and bacteria. A urinary examination was conducted and no pyuria was established. An examination of the skin did not reveal any significant pathogens, though septal fibrosis, fat lobules, and granulomatous inflammation were observed. The findings of the skin biopsy were consistent with erythema nodosum, which raised suspicions of coccidioidomycosis.

Although the patient's history and lifestyle did not reveal significant prior illnesses, a further health risk assessment indicated that he was at elevated risk of developing coccidioidomycosis. Coccidioidomycosis is mainly caused by Coccidioides immitis and Coccidioides posadasii. In the U.S., these species commonly occur in the southwestern region, especially California and Arizona (Chen, Lee & Li, 2010). In addition to geographic area, other risk factors include occupation, recreational activities, and racial background (Garcia et al., 2015). Construction and farm workers, individuals who engage in outdoor activities such as soil digging and hunting, and other populations with significant exposure to aerosolized dust environments are at greater risk of developing coccidioidomycosis compared to the general population (Wilken et al., 2015). Furthermore, Asian-Americans and African-Americans are more likely to be infected than individuals of other racial backgrounds. Therefore, on account of his occupation as a construction worker in California and his Asian background, the patient had a heightened risk for coccidioidomycosis.

Generally, treating coccidioidomycosis requires consideration of several factors: specifically, the advancement of pulmonary infection, the incidence of disseminated coccidioidomycosis, and the individual risk factors of the patient (Garcia et al., 2015). These considerations are crucial, as not every coccidioidomycosis patient requires treatment. Indeed, in most cases there may be no need to treat pulmonary coccidioidomycosis if there are no significant risk factors. Even so, with the increased availability of triazoles, symptomatic patients may be given antifungal treatments to minimize symptoms, though their effectiveness has not yet been fully established scientifically. It should be noted, however, that antifungal interventions do not treat hyper-reactive skin conditions (Garcia et al., 2015).