Background: Isotretinoin is well known in the therapy of acne papulopustulosa and acne conglobata. No study has investigated the pathophysiological changes of the skin of acne patients, especially when low dose oral isotretinoin is given in combination with topical tretinoin.
Patients and methods: 28 patients were treated for 6 months with oral isotretinoin. In the acne conglobata group (A-C) patients were treated with 10 mg (Group A) or 20 mg isotretinoin (Groups B, C) in combination with topical 0.05% tretinoin cream. Group C was treated the first 2 weeks with 0.05% betamethasone valerate cream instead of tretinoin cream. In the acne papulopustulosa group, the patients received 0.5 mg isotretinoin/kg bodyweight and 0.05% tretinoin cream, either alone (Group E), or with oral methylprednisolone during induction (Group D).
Results: Acne conglobata--A reduction of inflammatory lesion by 87-94% and of non-inflammatory lesions by 81-88% was achieved (Groups A-C). A reduction of sebaceous gland size by 35-58%, sebum production by 90-95%, follicular keratinization by 55-70% and Propionibacteria by 33-73% was seen (Groups B and C better than Group A). In Group A the amount of lipids was only reduced by 6%, in Group B by 35% and in Group C by 40%. Acne papulopustulosa--Sebum excretion rate and follicular keratinization were reduced in Group D by 89% and 50% respectively, with isotretinoin alone by 94% and 53%. The amount of lipids was reduced in Group D by 40% and in Group E by 21%.
Conclusions: Because of the efficacy and cost-benefit relationship of isotretinoin in the treatment of acne compared to other therapeutic approaches, further use low dose isotretinoin in the described settings seems to justified.