Pirfenidone-induced severe phototoxic reaction in a patient with idiopathic lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal pulmonary disease with an estimated 5-year survival of approximately 20%. Pirfenidone is a novel orally available antifibrotic agent that reduces disease progression and improves survival of patients with IPF. The most common adverse effects of pirfenidone include gastrointestinal symptoms, hepatic dysfunction or skin photosensitivity and rash. A 64-year-old male patient presented in our clinic with a strong generalized exfoliative erythema and intense itching accompanied by fatigue and mild fever after a mild sun exposure for 5 days during holidays in Turkey. The patient had been diagnosed with IPF 2 months ago and 1 month later he started a therapy with pirfenidone with good tolerability.

In this report, we noted a severe phototoxic reaction under treatment with pirfenidone which underlies the potential phototoxic effect of this drug besides the already reported photosensitivity.

Routine laboratory tests and a skin biopsy were performed.

Laboratory tests indicated increased markers of inflammation. The skin biopsy showed a perivascular lymphocytic inflammatory infiltrate, ballooning of keratinocytes with increased apoptosis. These findings were most consistent with a severe phototoxic reaction to pirfenidone which had been directly discontinued. The patient was started on oral methylprednisolone 100 mg/day which was gradually tapered off along with topical corticosteroids (mometasone furoate 0.1% cream) and oral antihistamines. This treatment led to a slow but complete resolution of the skin lesions within 20 days.

To our knowledge, this is the first reported case of a severe phototoxic reaction during treatment with pirfenidone. Our aim by presenting this case is to increase the awareness of clinicians for severe phototoxic effects of oral pirfenidone.