Untitled Document Onchocerciasis (river blindness) is an infectious disease common in west and central Africa, Central and South America, and the Arabian Peninsula. Onchocerciasis is the second leading infectious cause of blindness worldwide. Approximately 18 million people are infected with Onchocerca volvulus, of which 99% are in Africa.1 O volvulus is a filarial nematode, the etiologic agent of onchocerciasis. The most common cutaneous manifestations of onchocerciasis are intense pruritus, subcutaneous nodules, and localized erythematous papules and plaques with induration. Ocular pathology in onchocerciasis manifests as uveitis, punctate keratitis, and glaucoma. Diagnosis is made through slitlamp examination, as well as by demonstration of filarial worms on wet mount and hematoxylin-eosin (H&E) stained sections. Patients are treated with oral or intravenous ivermectin at a dose of 150 mg/kg once every 6 months for up to 10 years.2
We present the case of a US Army soldier originally from west Africa who was initially treated over a period of 2 years for conjunctivitis, uveitis, and a labile refractory glaucoma. After referral to ophthalmology and dermatology, a diagnosis of onchocerciasis was made. back to top
CASE REPORT A 37-year-old African man presented to the glaucoma clinic for evaluation of refractory glaucoma in his right eye and for possible trabeculectomy. Numerous microfilariae were noted in the anterior chamber of both eyes on slitlamp examination. The diagnosis of onchocerciasis was made, and the patient was referred to the infectious diseases clinic, where further examination revealed subcutaneous nodules in his left buttock and left axilla. He then was referred to dermatology.
The patient was a poor historian and spoke limited English. His medical history was significant for ongoing flares of bilateral conjunctivitis and chronic uveitis. Originally from Sierra Leone, west Africa, he emigrated to the United States with his family 3 years previously and thereafter enlisted in the US Army. The patient reported intermittent blurred vision for many years and episodes of severely irritated watery eyes. He had no current complaints of rash or pruritus, but as a younger man he remembered having intermittent pruritus in his left inguinal area and in both eyes. He denied ever having a rash or other skin discoloration. His wife also complained of visual problems. He also recalled that in his village of Sierra Leone, most elderly people were blind. His 2 children, who were born in Sierra Leone, also reported a history of pruritic skin and blurry vision but were currently asymptomatic.
Two years before presentation, the patient was diagnosed with primary open-angle glaucoma. He had experienced atypical exacerbations and remissions. He reported right temporal field visual loss and cloudy vision bilaterally for 5 years. In addition, he had a history of hepatitis B, malaria, and a positive purified protein derivative (tuberculin) skin test, for which he was treated with isoniazid for 6 months. The patient denied any history of surgery. He had no known drug allergies, and his only medications were ophthalmic timolol, latanoprost, and dorzolamide. The remainder of his review of systems was unremarkable.
The patient was of normal height and weight, alert and oriented, and in no acute distress. Bilateral conjunctival injection without drainage or exudate was noted. Results of a cutaneous examination revealed 2 soft, mobile, nontender masses. One mass in the left axilla was superficial and measured 1.5 cm in diameter, while the other in the left buttock was deeper in the dermis and measured 3.0 cm in diameter. No lymphadenopathy or edema was detected. No acute or chronic papular dermatitis, excoriations, lichenifications, fine wrinkles, or depigmentation characteristic of onchocerciasis were appreciated.
Laboratory test results for liver function, prothrombin time, international normalized ratio, partial thromboplastin time, and chemistry panel were within normal limits. The complete blood count demonstrated a mild eosinophilia of 8.6%. Hepatitis panel was consistent with a chronic carrier state for subdeterminants of hepatitis B surface antigen (+), hepatitis B surface antibodies (–), and hepatitis B e antigen (–). Thick and thin peripheral blood smears performed in the afternoon and at midnight showed no other parasitic infections.
Excisional biopsy of the nodule in his buttock was performed and yielded a 1x2-cm diameter mass of fatty tissue with intertwined, white, hairlike worms encased in a thick fibrous capsule (Figure 1). The number of worms in the nodule and their lengths were not determined. Excisional biopsy of the axillary mass was performed, and results revealed a steatocystoma on standard H&E sections. Perilesional skin snips also were obtained.