237inflammatory skin lesions after initiating biologic therapy [ 29 , 30 ]. While the timing
of these skin lesions occurring after initiation of anti-TNF therapy and their resolu-
tion after discontinuation of therapy suggest that they are induced by the biologic
agent, in some patients these inflammatory skin lesions may be an exacerbation of
pre- existing psoriasis or de novo psoriasis [ 30 ].
Psoriasiform Lesions
In a systematic analysis consisting of 1294 IBD patients treated with anti-TNF therapy,
21 (1.6%) of the patients (infliximab = 14, adalimumab = 7) were noted to have drug-
induced psoriasis [ 31 ]. Others have reported higher incidence of psoriasiform erup-
tions after initiation of anti-TNF therapy [ 3 , 26 , 27 , 32 ]. In a case control study, George
et al. found that 18/521 (3.5%) of patients with IBD developed anti-TNF- induced pso-
riasiform lesions [ 32 ]. In a study examining long-term safety of infliximab in patients
with IBD, as many as 150/734 (20%) of patients were observed to have psoriasiform
eruptions [ 3 ]. These inflammatory lesions occur approximately 12 months after anti-
TNF therapy, but onset after days to years has been reported [ 31 – 34 ].
Psoriasiform eruptions are characterized by scaly erythematous plaques with pus-
tulosis and possible nail involvement (see Figs. 14.1 and 14.2) [ 35 ]. These inflamma-
tory skin lesions have similar histological features as psoriasis: parakeratosis,
epidermal hyperplasia, epidermal lymphocytic infiltrates, dilated capillaries, and
intraepidermal pustulosis [ 25 , 36 ]. In a systematic literature review of cases of psoria-
sis developed during anti-TNF therapy among 41 IBD patients, Collamer et al. found
that plaque psoriasis was the most common form, seen in 25/41 (61%), followed by
pustular 20/41 (49%) and guttate 2/41 (5%) [ 36 ]. In 2011, Cullen et al. published a
case series as well as a review of the reported cases in the literature, with a total of
142 cases of anti-TNF-related psoriasis in IBD [ 34 ]. These authors have found that
the distributions of anti-TNF-related psoriasiform lesions are most common in the
palmoplantar and scalp, followed by trunk, flexures, and facial regions [ 34 ].
Fig. 14.1 Anti-TNF-induced
psoriasiform lesion
14 Noninfectious and Nonmalignant Complications of Anti-TNF Therapy