Bacterial pyomyositis in a patient with sickle cell trait and pityriasis amiantacea.
A 24-year-old black woman with history of primary hypertension and sickle cell trait (SCT) presented to the hospital with fever (38.5°C) and painful right-sided swelling of her neck for 2 days. She had no history of immunocompromise caused by diabetes mellitus, hepatitis or human immunodeficiency virus (HIV) infection. There was no history of intravenous drug use, recent travel, insect bites, strenuous exercise or trauma to the area. Physical examination revealed erythema and tender edema overlying the right sternocleidomastoid muscle with impaired ipsilateral flexion and contralateral rotation (Figure 1, left), along with retroauricular and jugular lymphadenopathies. She also had generalized gray thick scales adhered to her scalp consistent with pityriasis amiantacea (PA) (Figure 1, right), which had been present for 6 months; they were pruritic and she had multiple excoriations from scratching. Laboratory studies showed leucocytosis (18.3 × 109 cells/l) with neutrophilia, and no immature forms. Computed tomography of the neck showed inflammatory changes of the right sternocleidomastoid muscle and a small fluid collection (Figure 2). The diagnosis of stage two (suppurative) bacterial pyomyositis was made, and treatment with intravenous cefazolin was started. 



Figure 1. 
(Left) Right-sided tender swelling of the neck. (Right) Shiny asbestos-like silvery scales binding tufts of hair covering almost the entire scalp, representing pityriasis amiantacea.





Figure 2. 
(Left) Coronal view …