[1] Hallym Univ, Div Pulm Allergy & Crit Care Med, Dept Internal Med, Chuncheon Sacred Heart Hosp, Chuncheon Si, South Korea
[2] Catholic Univ Korea, Div Pulm Allergy & Crit Care Med, Dept Internal Med, Seoul St Marys Hosp,Coll Med, Seoul, South Korea
[3] Ulsan Univ Hosp, Internal Med, Ulsan, South Korea