Spontaneous pneumomediastinum secondary to profound weight loss and malnutrition: a case report and review of malnutrition as a primary etiology

Abstract

Spontaneous pneumomediastinum (SPM) is a rare but significant complication of anorexia nervosa (AN). While historically linked to Valsalva maneuvers, a growing body of evidence implicates severe malnutrition as an associated risk factor, challenging traditional etiologic models. To describe a case of SPM in a patient with profound weight loss and malnutrition without classic triggers and review the literature on malnutrition as a contributing factor. We present the case of a 23-year-old male with rapid weight loss (80 kg over 7 months) and a body mass index (BMI) of 17 kg/m 2 (DSM-5 mild severity) who developed exertional dyspnea and subcutaneous emphysema in the absence of vomiting, coughing, trauma, or evidence of covert purging. Computed tomography confirmed isolated SPM; a CT of the abdomen performed at an outside center was normal, excluding intra-abdominal pathology. Symptoms resolved completely with eight days of conservative management and intensive nutritional rehabilitation, during which he gained 1.5 kg. Male cases of AN are statistically rare, which further increases the clinical interest of this presentation. This case reinforces the association between rapid weight loss/malnutrition and SPM pathogenesis. A narrative review of the literature reveals a broad clinical spectrum, ranging from benign, self-limited presentations to a more severe presentation characterized by multi-compartmental air leaks and cardiopulmonary compromise. The patient's BMI of 17 kg/m 2 (mild severity) contrasts with most prior cases (BMI 10–14), suggesting that the rate of weight loss (~11 kg/month) may be more pathophysiologically relevant than absolute BMI. SPM is a critical complication of rapid weight loss and malnutrition that can occur without classic triggers. Clinicians should recognize its potential for recurrence and, rarely, for severe progression. This report synthesizes current evidence to provide a framework for diagnosis, risk stratification, and comprehensive management. Future research should focus on identifying biomarkers of tissue fragility, including prealbumin, rate of weight loss, and low BMI.