Why a loss of hearing is a common but overlooked vasculitis warning sign
Problems seen for half of people with 2 AAV types assessed in small study
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Hearing loss is common among people with two types of ANCA-associated vasculitis (AAV), affecting half of those assessed in a small study in Saudi Arabia, according to researchers.
Following audiological and other assessments, the team found loss of hearing in about 50% of participants with granulomatosis with polyangiitis (GPA) and eosinophilic granulomatosis with polyangiitis (EGPA), two of the three main types of AAV.
Some cases were subclinical, meaning hearing problems were detected via testing, though patients did not report symptoms. Hearing loss was associated with an older age at diagnosis and longer disease duration, but its rate and type did not differ significantly between GPA and EGPA patients, the researchers found.
The team noted that “ear, nose and throat (ENT) involvement is a frequent and early manifestation of” AAV. In this patient population, “hearing loss is frequent and often subclinical, highlighting the importance of audiometric [hearing] and tailored ENT assessments,” the researchers wrote.
The study, “Ear-nose-throat manifestations of granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis: a cross-sectional study,” was published in the journal Rheumatology International.
AAV is a group of autoimmune diseases in which self-reactive antibodies called ANCAs drive inflammation that damages small blood vessels. This, in turn, can impair organ function, leading to problems with the lungs and kidneys, and/or causing upper respiratory and ENT issues.
GPA is one of the most common types of AAV, while EGPA is the rarest. Regardless of type, ENT involvement is one of the most common features of AAV and can appear early, sometimes months before the disease is diagnosed. Because these symptoms may be mistaken for infections or allergies, recognizing AAV as a possible cause is important to help prevent permanent organ damage.
20% of patients found to have unreported hearing loss
To better understand these manifestations, a research team evaluated and compared ENT and airway involvement in 35 adults with GPA and 15 with EGPA. The participants were recruited at a single center in Saudi Arabia, and their mean age at diagnosis was 35.4 years.
Upper airway involvement was the most common manifestation, affecting 90% of participants overall. This was followed by lung, affecting 60%, kidney issues, seen for 28%, and neurologic involvement, experienced by 24%. Lung involvement was significantly more frequent in EGPA than GPA patients (93% vs. 46%), as was neurologic involvement (53% vs. 11%).
A total of 48 participants younger than 60 had hearing data available. Hearing loss was the most common ear-related manifestation, affecting about 50%, with no significantly different rates between the two groups.
[The findings regarding unreported hearing loss underscore] the need for regular assessment of hearing symptoms and periodic [hearing] testing during follow-up.
Clinical hearing loss, meaning symptoms were present and confirmed by testing, was found in 14 patients (29%). Another 10 patients (20%) had no symptoms, but abnormal hearing tests consistent with subclinical hearing loss. Sensorineural hearing loss, which results from problems in the inner ear or hearing nerve, was the most common type, the researchers noted.
According to the team, the findings regarding subclinical hearing loss underscore “the need for regular assessment of hearing symptoms and periodic audiometric testing during follow-up.”
Loss of hearing was more common in participants diagnosed at age 34 or older than in those diagnosed at an earlier age. It was also associated with having had AAV for a longer time: Individuals with hearing loss had a median disease duration of eight years, compared with 1.5 years among those without hearing loss.
Nose and sinus symptoms found, but these varied by AAV type
Problems in the nose and sinus, which are air-filled cavities in the face, differed between GPA and EGPA patients, the researchers found. Those with EGPA were significantly more likely to have inflammation of the sinuses on both sides of the face (100% vs. 63%), nasal cavity swelling (93% vs. 57%), and chronic nasal inflammation (87% vs. 54%). Nasal noncancerous growths were also significantly more common among EGPA patients than those with GPA (40% vs. 6%).
By contrast, destructive lesions — areas of damage with erosion of bone and cartilage — and unilateral sinus inflammation were only associated with GPA. Lesions were reported for 31% of patients, while inflammation was seen among 29%.
Laryngeal involvement, affecting the voice box area, was present in 46% of participants, with comparable rates between the GPA and EGPA groups. The most common laryngeal finding was swelling or redness of the laryngeal wall, seen in 24%, followed by hoarseness in 20%; these did not differ between the groups.
Subglottic stenosis, or narrowing of the airway just below the vocal cords, also occurred only in the GPA group, affecting 14% of patients. This is a challenging GPA manifestation, the team noted, because it may lead to upper airway obstruction and, in severe cases, require a surgical opening in the windpipe to help with breathing.
Among the study limitations noted by the team were its small size and cross-sectional design, meaning patients were assessed at a single point in time. Despite this, the findings show that ENT involvement is common in both GPA and EGPA, with distinct patterns depending on disease type, the researchers noted.
According to the team, studies following patients over time “are needed to better define the clinical significance of these findings and to evaluate the role of routine audiometric assessment in patients with AAV.”
The researchers noted that the use of “systematic ENT evaluation [enabled] detection of subclinical … disease that may have been overlooked in cohorts relying solely on retrospective chart review.”
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