Photoallergy to systemic quinidine in the mouse: dose-response studies.

Photoallergic dermatitis was induced in the mouse following the systemic administration of quinidine in combination with UVB and UVA. The reaction was recorded as ear wet weight, ear thickness and tail wet weight. Statistical calculations showed ear wet weight to be the most sensitive evaluation technique. By varying the quinidine dose administered in induction (2.5-100 mg/kg) and challenge (10-100 mg/kg), dose-response conditions were established. It was shown that the induction dose necessary to obtain a statistically significant reaction was considerably lower than the minimal challenge dose (25 mg/kg). This method is well suited for studies of the dynamics of the induction and elicitation phases of systemically induced photoallergy.