A 72-year-old Indian male with follicular lymphoma treated with chemotherapy and immunotherapy presented to our center with a four day history of right-sided facial droop, dysphagia and hoarseness. The patient had a one-year history of recurrent sinus and ear infections and was evaluated at an outside hospital for a nasopharyngeal (NP) mass. Biopsy of the mass revealed normal epithelial cells and the culture grew Pseudomonas aeruginosa. The patient received several courses of antibiotics and steroids without symptomatic improvement in his ear pain.
At the time of presentation to our center, he had right-sided facial droop and sensorineural hearing loss. His labs were notable for a leukocytosis and an elevated erythrocyte sedimentation rate. MRI disclosed abnormal signal and enhancement in the posterior nasopharynx with extension into the retropharynx, prevertebral space, anterior clivus, carotid space, jugular fossa and stylomastoid foramen. Right ear aspirate cultures grew multi-drug resistant (MDR) P. aeruginosa. The patient was initiated on a six-week course of ceftolazone-tazobactam. Culture of purulent fluid from the nasopharynx was positive for Candida glabrata and Prototheca wickerhamii in addition to MDR P. aeruginosa. A seven-day course of liposomal amphotericin B was initiated until the sensitivities of Candida and Prototheca became available, after which the patient was switched to a five-week course of posaconazole. Repeat imaging two weeks following the initiation of posaconazole showed increased extension of disease. A repeat NP biopsy was done and again showed C. glabrata and P. wickerhamii both sensitive to micafungin. The patient was transitioned to micafungin and received hyperbaric oxygen therapy with improvement in symptoms and on imaging four weeks later.
Discussion:
P. wickerhamii is an achlorophyllous alga that rarely causes infections in humans. Non-cutaneous infections usually occur in immunocompromised patients and are associated with significant morbidity and mortality. There is little evidence to support a definitive treatment strategy for human protothecosis.1 Here we report a case of nasopharyngeal infection with extension into the skull base and neck tissues in an immunocompromised host caused by P. aeruginosa, C. glabrata and P. wickerhamii that initially progressed on imaging despite treatment with targeted antibiotics and antifungals (ceftolazone-tazobactam and posaconazole) but responded following changing the antifungal treatment to micafungin and addition of hyperbaric oxygen therapy.
Conclusions:
P. wickerhamii is an achlorophyllous alga that causes severe infections in humans. There is little evidence to support a definitive treatment strategy. Combined treatment with micafungin and hyperbaric oxygen therapy may be an effective treatment option.
1Lass-Florl, C., and A. Mayr. “Human Protothecosis.” Clinical Microbiology Reviews 20.9 (2007): 230-42. Pubmed. Web. 01 Nov. 2016.