[Clinical and imaging features of acute histoplasmosis]

Objective: To investigate the clinical and imaging characteristics of acute histoplasmosis. Methods: The clinical and imaging data of 10 patients with acute histoplasmosis were studied. Their clinical and imaging characteristics were analyzed. All the patients returned from a South American republic in April 2019 and were treated at the Chongqing public health medical treatment center. Results: All the 10 patients were male, aged 30-56 years old, with an average age of 43.8 years old. Four of them were engaged in soil clearing, 2 in gas cutting, 2 in moving tools, and 2 in inspection. The disease in all the 10 patients was caused by inhaling a large amount of bacteria-bearing dust in a short time, with an incubation period of 9-13 days, and the main clinical manifestations were fever, insomnia, dizziness, headache, cough, poor appetite, rash and diarrhea. One patient's head CT showed extensive thickening and increased density of bilateral frontotemporal, parietal and occipital meninges, while the other 9 patients showed no obvious abnormalities. Chest CT findings were as follows: (1) Multiple nodular shadow: the chest CT findings of 4 patients were miliary nodular shadow with diffuse distribution in both lungs. Most of the nodules were less than 5 mm in diameter and distributed evenly or unevenly. CT findings of 6 cases showed scattered nodular shadows in both lungs, with diameters ranging from 2 to 15 mm, and obvious distribution in subpleural and inferior lobes of both lungs. (2) Consolidation shadow: in 2 cases, the size of the shadow was uneven and the density increased, mainly distributed in the subpleura and the lower lobe of both lungs. (3) Ground glass density shadow: mainly distributed around nodules, halo signs can be seen around some nodules. (4) Mediastinum and/or hilar lymph nodes were enlarged. (5) Pleural effusion: a small amount of pleural effusion was found in 4 cases. (6) Pericardial effusion in 3 cases. Abdominal CT showed splenomegaly in 8 cases and hepatomegaly in 1 case. Conclusions: Acute histoplasmosis has no specificity in clinical manifestations. However, there are still some features in CT manifestations, including multiple nodules in both lungs accompanied by halo, enlarged liver, spleen and mediastinal lymph nodes, and multiple serous cavity effusions.