Stevens-Johnson syndrome and toxic epidermal necrolysis: follow-up of pulmonary function after remission.

Acute-stage specific bronchial epithelial detachment has been described in 27% of patients with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). To assess the pulmonary function of patients with SJS/TEN after remission. Analysis of pulmonary function tests (PFTs) performed during the usual follow-up of patients with SJS/TEN managed in a referral centre from April 2007 to January 2010. Of 58 patients admitted, 32 underwent PFTs (17 male, 15 female). The median time from the acute stage to PFTs was 3 months (interquartile range 1-18). Three patients had grade 2 dyspnoea. Eighteen patients (56%) had abnormal PFTs, including 13 patients (41%) with moderately altered diffusion capacity for carbon monoxide (DLCO ) normalized by the alveolar volume (VA) (giving the ratio KCO , which equals DLCO /VA) and five patients with decreased total lung capacity. No airway obstruction was observed. Patients with decreased KCO had higher initial detached body surface area than others (30% vs. 10%, P = 0·006), as did those with decreased DLCO (25% vs. 10%; P = 0·054). There were correlations between detached body surface area and both KCO (r = -0·41, P = 0·026) and DLCO (r = -0·47, P = 0·011). Among 10 patients with decreased KCO on the first PFT, eight patients had a sustained decrease in KCO on a second PFT. More than half of patients with SJS/TEN displayed abnormalities on PFTs, mainly diffusion impairment, which was associated with higher initial skin surface detachment. These abnormalities were mostly asymptomatic and remained stable over time.