We recorded higher incidences of treatment-related grade 3 diarrhoea with afatinib ( 39 [ 10 % ] vs nine [ 2 % ] ) , of grade 3 stomatitis with afatinib ( 16 [ 4 % ] vs none ) , and of grade 3 rash or acne with erlotinib ( 23 [ 6 % ] vs 41 [ 10 % ] ) .