Paraneoplastic pemphigus with airway involvement.

We report a case of paraneoplastic pemphigus presenting with acute hypoxemic respiratory failure due to bronchiolitis obliterans which improved with high dose systemic corticosteroids, rituximab, niacinamide and doxycycline. This is the first report, to our knowledge, of paraneoplastic pemphigus with airway involvement which included niacinamide and doxycycline as therapy and demonstrated treatment response.