Hypersensitivity reactions
Cutaneous eruptions induced by IFNs are common, with an incidence of
13-23% (111,112). Localized reactions
at injection sites are most frequent at 48 weeks
(113). Diffuse skin symptoms including
urticaria, generalized eczema, papules are common and mostly treated
with symptomatic treatment (111,114,115). Among 26 patients with
non-immediate reactions to IFNs, 12 cases reported generalized eczema,
10 MPE, 3 generalized urticaria and 1 lichenoid eruption (116). Cases of
FDEs (117), and subacute cutaneous lupus
(118) were described.
There are few case reports of immediate urticaria
(119,120) and anaphylaxis (121,122). For
IHRs to IFN-β, positive STs were reported (119,121). For NIHRs, PTs have
a low value and are not recommended, whereas delayed reading IDTs are
useful (116,123). A positive DPT was
reported in a patient experiencing anaphylaxis due to peg-INF-α2a with
negative STs (122). Successful
desensitization protocols both for IHRs (120) and NIHRs (116,124) due to
different IFNs were reported.