Anti-inflammatory effects of 13-Cis-retinoic acid. An in vivo study.

Sixteen patients with care acne conglobata, acne fulminans, acme tetrade were treated orally with 13-cis-retinoic acid, 1-2 mg/kg body weight for 12 weeks. A maintenance dose of 0.5 mg/kg in ten cases and the use of no further medication in six other cases for an additional 12 weeks followed. A 40% potassium iodide ointment was used on the upper back under occlusive dressing conditions to induce an inflammatory reaction. Four inflammatory parameters were assessed in all subjects before and during oral treatment: erythema (0-2+), edema (0-2+), papules (numbers), and pustules (numbers). All patients showed excellent improvement. Additionally, the inflammatory reaction in all patch-tests was significantly reduced: erythema from 1.13 to 0.34 (P less than or equal to 0.01); edema from 1.06 to 0.25 (P less than or equal 0.0005); papules from 6.75 to 1.86 (P less than or equal to 0.01); and pustules from 10.44 to 1.56 (P less than or equal to 0.0025). We suggest that 13-cis-retinoic acid acts as a strong anti-inflammatory agent in addition to its known function as a sebostaticum.