Sparfloxacin-induced photosensitivity and the occurrence of a lichenoid tissue reaction after prolonged exposure.

BACKGROUND

A new antibacterial quinolone, sparfloxacin (SPFX), frequently causes photosensitive dermatitis and sometimes induces a treatment-resistant lichenoid tissue reaction (LTR).

OBJECTIVE

We attempted to determine the factors that induce LTR in SPFX-induced photodermatitis.

METHODS

Thirteen patients with SPFX photosensitive dermatitis were studied clinically and histopathologically.

RESULTS

Six of the 13 patients had acute dermatitis with epidermal spongiosis and focal epidermal HLA-DR and intercellular adhesion molecule-1 (ICAM-1) expression with CD4+ cell infiltration. The other seven displayed LTR with basal cell liquefaction degeneration and diffuse epidermal HLA-DR and ICAM-1 expression associated with CD8+ cells. The seven patients with LTR were exposed to UV and SPFX for more than 2 weeks after the appearance of their initial eruption, whereas the six patients with acute dermatitis were treated within 2 weeks. The acute dermatitis lesions cleared significantly within 2 weeks, but the LTR lesions persisted for more than 6 weeks.

CONCLUSION

Patients with quinolone-induced photosensitivity should be treated within 2 weeks of onset to prevent LTR.