The clinical characteristics of pharyngeal and laryngeal lesions in anti-MDA5-positive dermatomyositis patients.

Objectives: To investigate the clinical characteristics of pharyngeal and laryngeal lesions in patients with anti-melanoma differentiation-associated gene 5 antibodies-positive dermatomyositis (anti-MDA5-positive DM).

Methods: Serological indicators of 131 anti-MDA5-positive DM patients were analysed. All 35 patients with pharyngeal and laryngeal symptoms underwent electronic laryngoscopy examinations.

Results: Pharyngeal and laryngeal symptoms were observed in 26.7% of anti-MDA5-positive DM patients. Low levels of haemoglobin, albumin, prealbumin, high-density lipoprotein and rapidly progressive interstitial lung disease mainly appeared in patients with pharyngeal and laryngeal involvement compared to those without involvement. However, no significant difference in mortality was found between the two groups. The number of patients with pharyngeal and laryngeal involvement was significantly higher in anti-Ro-52 antibody-positive patients than in anti-Ro-52 antibody-negative patients. Patients with higher serum ferritin levels (1000 ng/ml ≤ serum ferritin ≤ 1500 ng/ml) were more likely to develop pharyngeal and laryngeal involvement compared to those with lower serum ferritin levels (serum ferritin < 500 ng/ml). Electronic laryngoscopy examinations effectively assisted rheumatologists in assessing the conditions of the pharyngeal mucosa, arytenoid area, epiglottis, and vocal cords. Some patients also presented with rare lesions such as pharyngeal posterior wall fistulas, epiglottic ulcers, and vocal cord white lesions.

Conclusions: 1. Pharyngeal and laryngeal lesions are not uncommon in anti-MDA5-positive DM, these patients have poorer nutritional status and more severe lung lesions; 2. Positive anti-Ro-52 antibodies and high serum ferritin levels are closely associated with pharyngeal and laryngeal involvement in anti-MDA5-positive DM; 3. Electronic laryngoscopy plays a crucial role in the diagnosis and evaluation of pharyngeal and laryngeal conditions.