Dimorphic fungi characteristics — MCQs

An 18-year-old man presents to the office, complaining of an itchy patch on his torso that appeared one week ago. The patient is on the college wrestling team and is concerned he will not be able to compete if it gets infected. He has no significant medical history, and his vital signs are within normal limits. On examination, there is an erythematous, scaly plaque with central clearing at approximately the level of rib 6 on the left side of his torso. What diagnostic test would be most appropriate at this time?

An investigator is studying growth patterns of various fungal pathogens. Incubation of an isolated fungus at 25°C shows branching hyphae with rosettes of conidia under light microscopy. After incubation at 37°C, microscopic examination of the same organism instead shows smooth, white colonies with rounded, elongated cells. Infection with the investigated pathogen is most likely to cause which of the following conditions?

An investigator is studying the growth of an organism in different media. The organism is inoculated on a petri dish that contains heated sheep blood, vancomycin, nystatin, trimethoprim, and colistin. The resulting growth medium is incubated at 37°C. Numerous small, white colonies are seen after incubation for 48 hours. This organism is most likely to cause which of the following conditions?

A 47-year-old woman comes to the physician because of a 3-day history of fever, fatigue, loss of appetite, cough, and chest pain. Physical examination shows diffuse inspiratory crackles over the left lung field. An x-ray of the chest shows hilar lymphadenopathy and well-defined nodules with central calcifications. Urine studies show the presence of a polysaccharide antigen. A biopsy specimen of the lung shows cells with basophilic, crescent-shaped nuclei and pericellular halos located within macrophages. This patient's history is most likely to show which of the following?

A 16-year-old boy presents to his pediatrician because he has noticed white plaques forming on his tongue over the last 5 days. He recently returned from a boy scout trip where he traveled across the country and hiked through the woods. His past medical history is significant for asthma for which he uses an inhaler as needed. He says that during the trip he felt short of breath several times and had to use the inhaler. He also says that several of his friends appeared to get sick on the same trip and were coughing a lot. He has not experienced any other symptoms since returning from the trip. On presentation, he is found to have white plaques on the tongue that can be scraped off. Which of the following is a characteristic of the most likely cause of this patient's disease?

A 40-year-old farmer from Ohio seeks evaluation at a clinic with complaints of a chronic cough, fevers, and anorexia of several months duration. On examination, he has generalized lymphadenopathy with hepatosplenomegaly. A chest radiograph reveals local infiltrates and patchy opacities involving all lung fields. Fine needle aspiration of an enlarged lymph node shows the presence of intracellular yeast. A fungal culture shows the presence of smooth, thin-walled microconidia and tuberculate macroconidia. Which of the following is the most likely diagnosis?

A 44-year-old man comes to the physician because of a 3-week history of productive cough, fever, and lethargy. He also has several skin lesions over his body. His symptoms began 3 weeks after he returned from a camping trip in Kentucky. Three years ago, he underwent kidney transplantation for polycystic kidney disease. Current medications include sirolimus and prednisone. His temperature is 38°C (100.4°F). Diffuse crackles are heard over the lung fields. There are 4 white, verrucous skin patches over his chest and upper limbs. A photomicrograph of a skin biopsy specimen from one of the lesions is shown. Which of the following is the most likely diagnosis?

A young woman from the Ohio River Valley in the United States currently on corticosteroid therapy for ulcerative colitis presented to a clinic complaining of fever, sweat, headache, nonproductive cough, malaise, and general weakness. A chest radiograph revealed patchy pneumonia in the lower lung fields, together with enlarged mediastinal and hilar lymph nodes. Skin changes suggestive of erythema nodosum (i.e. an acute erythematous eruption) were noted. Because the patient was from a region endemic for fungal infections associated with her symptoms and the patient was in close contact with a person presenting similar symptoms, the attending physician suspected that systemic fungal infection might be responsible for this woman’s illness. Which of the following laboratory tests can the physician use to ensure early detection of the disease, and also effectively monitor the treatment response?

A 29-year-old woman comes to the military physician because of a 2-day history of fever, joint pain, dry cough, chest pain, and a painful red rash on her lower legs. Two weeks ago, she returned from military training in Southern California. She appears ill. Her temperature is 39°C (102.1°F). Physical examination shows diffuse inspiratory crackles over all lung fields and multiple tender erythematous nodules over the anterior aspect of both legs. A biopsy specimen of this patient's lungs is most likely to show which of the following?

A 19-year-old woman presents to the family medical center with a 2-week history of a sore throat. She says that she has felt increasingly tired during the day and has a difficult time staying awake during her classes at the university. She appears well-nourished with a low energy level. Her vital signs include the following: the heart rate is 82/min, the respiratory rate is 14/min, the temperature is 37.8°C (100.0°F), and the blood pressure is 112/82 mm Hg. Inspection of the pharynx is depicted in the picture. Palpation of the neck reveals posterior cervical lymphadenopathy. The membrane does not bleed upon scraping. What is the most specific finding for detecting the syndrome described in the vignette?