Limited data exist on the clinical presentation of Muckle–Wells syndrome (MWS) during pregnancy. The purpose of this case report is to highlight the diagnosis of MWS in a pregnant woman. Many rheumatic diseases affect women of childbearing age, and their management during pregnancy can be challenging.
Case
A 33-year-old, 18-weeks’ pregnant woman was hospitalized for acute pain and swelling in her right knee. There was no preceding trauma, diarrheal illness, throat infection or tick exposure. She denied fevers, chills or rashes. She recalled a history of urticaria, precipitated by cold temperatures and prior episodes of vague joint pain.
On physical exam, she was afebrile without skin rashes. Her right knee revealed a large effusion associated with tenderness and warmth with limited range of motion. X-ray and MRI of the right knee showed a joint effusion. ESR was elevated at 57 mm/hr (reference range: 0–29 mm/hr), and CRP was 2.3 mg/dL (reference range: 0–10 mg/dL). Joint aspiration revealed an inflammatory infiltrate with 38,500 WBCs, 94% neutrophils and no crystals.
All cultures, ANA, rheumatoid factor, Lyme serology and HLA B27 antigen returned negative.
She was treated with intravenous ceftriaxone and ibuprofen with significant improvement. The remainder of her pregnancy was unremarkable.
Eight weeks postpartum, the patient noticed sudden deterioration in her hearing, along with subjective fever and fatigue. Audiometric studies were consistent with bilateral moderate sensorineural hearing loss. MRI of the brain and 8th cranial nerve were unremarkable. Treatment with oral prednisone, acyclovir and intratympanic steroid injections was not beneficial, and the patient experienced an ongoing decline in her hearing.
One year later, when she was 12 weeks’ pregnant, the patient noted repeat swelling and pain of her right knee. ESR was elevated at 47 mm/hr, and CRP was 4.1 mg/dL. The NLRP3 gene was sent for analysis. The R262W missense mutation was found, consistent with a diagnosis of Muckle–Wells syndrome. She was started on anakinra 100 mg/daily with significant improvement in well-being. After two weeks, her ESR had fallen to 1.0 mm/hr and CRP normalized at 1.0 mg/dL. The remainder of her pregnancy was without event, and her hearing loss stabilized.
Discussion
This case illustrates the unusual clinical presentation of Muckle–Wells syndrome as an inflammatory monoarticular arthritis during pregnancy. MWS is an inherited, autosomal-dominant, auto-inflammatory disorder, presenting with a variety of symptoms, including periodic fever, rash and arthralgia, as well as sensorineural hearing loss and the development of AA amyloidosis, the latter of which implies a poor prognosis.1 It was first identified by Thomas Muckle, MD, and John Wells, MD, in 1962 as a series of case reports of sensorineural deafness, urticaria and amyloidosis, affecting nine members of a family in Britain.2