A Chronic, Scaly Rash Mistaken for MRSA: Case Presentation

A 22-year-old man presents to the emergency department (ED) with a scaly, verrucous rash involving the side of his nose (shown). Approximately 2 weeks prior to presentation, the patient had been treated in the ED for the same rash. At the initial presentation, he had just recently moved from California’s Central Valley and had no other symptoms. Methicillin-resistant Staphylococcus aureus was initially diagnosed, and the patient was treated with a 10-day course of trimethoprim/sulfamethoxazole and rifampin and discharged. He returned for this second visit because his rash is no better and he is now experiencing night sweats, arthralgia, and back pain.

On physical examination, a lesion is visible on his posterior left shoulder (shown). He is tachycardic at 120 bpm, his blood pressure is 100/85 mm Hg, respiratory rate is 18 breaths per minute, and he has a normal temperature and oxygen saturation. His cardiovascular and respiratory examinations are unremarkable, but he has point tenderness over the right clavicle, lower vertebral bodies, and the anterosuperior iliac spine of the left hip. There is no abdominal tenderness.

What does the patient’s chest radiograph (shown) indicate?
A. Left upper lobe nodule
B. Cardiomegaly
C. Increased perihilar cuffing
D. Lobar pneumonia

Answer: A. Left upper lobe nodule

What initial laboratory examinations should you order?
A. Complete blood count, troponin
B. Complete blood count, erythrocyte sedimentation rate, creatinine level
C. Erythrocyte sedimentation rate, sputum culture
D. Sputum culture, blood culture, and biopsy of the nodule

Answer: B. Complete blood count, erythrocyte sedimentation rate, creatinine level

The patient’s laboratory values are shown. Based on these values and the patient’s physical examination, the patient is admitted to the hospital for further workup and evaluation in consultation with an infectious disease specialist.

What is the most likely diagnosis at this point?
A. Blastomycosis
B. Histoplasmosis
C. Coccidioidomycosis
D. Sarcoidosis

Answer: C. Coccidioidomycosis

Recall from the patient’s history that he recently moved from California’s Central Valley. Coccidioidomycosis (commonly referred to as “valley fever ”) is a fungal infection caused by inhalation of the spores of Coccidioides immitis. Coccidioidomycosis is endemic to the semi-arid areas of the southwest United States, particularly central California, Arizona, and parts of Texas (shown), as well as Mexico and parts of South America.

Image courtesy of the Centers for Disease Control and Prevention.

Epidemiologic studies show that 50-60% of patients with coccidioidomycosis have no symptoms, whereas 40% develop flu-like symptoms. About 10% develop pulmonary disease and a small percentage of patients develop disseminated disease, usually with involvement of the skin (as with the abscess shown), bones, and central nervous system (CNS). Less than 1% of patients experience CNS involvement, which is associated with the greatest morbidity and mortality and is generally fatal without treatment; these patients frequently require lifelong treatment.

The incubation period of coccidioidomycosis is usually 10 to 16 days, with a range of < 7 days to 30 days.^[1] The clinical manifestations of coccidioidomycosis depend on the organs involved. On clinical examination, patients who live in endemic regions or who have traveled to endemic regions may present with insidious symptoms of cough, fever, chills, night sweats, weight loss, myalgia, or fatigue. Patients may also present with a rash, bone pain, and/or meningeal symptoms. Erythema nodosum (shown) can be seen in about 25% of patients and is considered a good prognostic marker.

The diagnosis of coccidioidomycosis is often made by performing a serologic test (a coccidioidomycosis panel, which is an enzymatic immunoassay). The anticoccidioidal compliment fixation titer indicates the severity of infection. Titers of 1:32 or greater should be followed by bone scanning and lumbar puncture to evaluate for dissemination. Chest radiographs may show a simple lobar pneumonia, multilobar involvement, mass-like airspace lesions (shown), cavitary lesions, empyema, or effusions.

In patients with osteomyelitis, bone radiographs may show lytic lesions, periosteal elevation, and bony destruction (shown). Bone involvement should be further evaluated with magnetic resonance imaging (MRI). Meningeal symptoms can be evaluated by performing a lumbar puncture and examining the cerebrospinal fluid. If imaging of the brain is considered, MRI is more sensitive than computed tomography for detecting lesions. Biopsy samples of associated lesions can grow in almost any culture medium, and any sample suspected of being positive should be appropriately labeled as a biohazard.

Signs of severe disease are shown. Mild infection does not require treatment. Moderate infection may be treated with either fluconazole or itraconazole. Patients with moderate to severe infection, according to the severity indicators, and patients with risk factors for dissemination may warrant treatment with amphotericin. The objectives of treatment are resolution of infection, decrease of antibody titers, return of function of involved organs, and prevention of relapse.

Risk factors for dissemination are shown. In the decision-making process for treatment, significant weight is given to the severity of infection, risk factors for dissemination (including race and ethnicity, extremes of age, immunologic status), any severe comorbidity (eg, diabetes, pregnancy, significant preexisting vital organ dysfunction, negative skin test results), and serum complement-fixation IgG titer.^[1-12]

Medical treatment options are shown. Although most treatment is with amphotericin, itraconazole is thought to have better bone penetration, whereas fluconazole has better CNS penetration. Surgical intervention is required in certain cases, such as those with bony involvement or progressive pericardial effusion. Newer pharmacologic agents, including voriconazole and posaconazole, are also being investigated for patients who have progressive disease resistant to standard therapy.^[13-15]

The prognosis for uncomplicated disease is good. After the infection resolves, the individual has lifelong immunity to repeat infection. In cases of complicated disease, such as diffuse pulmonary involvement (shown here by computed tomography) and/or disseminated disease, patients may have substantial morbidity, depending on the areas of involvement. Although no practical methods of prevention are available, there are vaccines currently undergoing clinical investigation.

The patient in this case was initially placed on fluconazole at 800 mg/day. Because of the presence of high titers and systemic symptoms, further workup was performed to evaluate for systemic involvement. A bone scan showed multiple areas of increased uptake (shown) in the facial bones and the clavicle, in several vertebral bodies, and in both hips. With input from an infectious disease specialist, the dosage of fluconazole was increased to 1200 mg/day and the patient was kept in the hospital for several days. Eventually, the systemic symptoms resolved and the patient was discharged home, continuing oral fluconazole therapy and undergoing close follow-up.