1. Lichenoid drug eruption due to initiation of IFN alfa therapy for hepatitis C virus infection -case report- Andreea Stancu*, Aurel Doru Chirita**, Irina Margaritescu** * „Carol Davila” University Emergency Central Military Hospital, Bucharest ** "Domina-Sana" Medical Center Bucharest.

2. Introduction Interferon alpha is the treatment of choice for chronic hepatitis C virus (HCV) infection Cutaneous reactions to interferon therapy, both local and distant from the injection site, are not uncommon Eczematous and lichenoid reactions are most commonly reported Cutaneous adverse reactions were more common in the combined IFN/ribavirin than in the IFN monotherapy in literature

3. Clinical case We report the case of a 62-year-old man undergoing treatment with interferon alpha therapy for hepatitis C, who developed a lichenoid drug eruption associated with interferon injections

4. Clinical case  Initial lesions located at the injection site

5. Clinical case  Typical well-circumscribed papules on the anterior aspects of forearm

6.  A widespread subsequent eruption of pruritic papules on the trunk and abdomen

7.  Superficial lichenoid dermatitis, perivascular and perianexial (infundibulofollicular)

8.  basal vacuolar changes with obscuration of dermoepidermal jonction  necrotic keratinocytes  scattered melanophages occupied in the papillary dermis

9. Conclusions Dermatologic side effects of IFN alpha have included skin rash, injection site reaction, diaphoresis, partial alopecia, dry skin, pruritus, hematoma Interferon therapy has also been associated with the occurrence or worsening of a number of dermatologic disorders The skin reaction at the injection site is a strong argument that supports our diagnosis To our knowledge, this is one of a few reported cases of a lichenoid drug reaction triggered by interferon