The aim of the present study was to investigate the effect of a combination of triiodothyroacetic acid (TRIAC) and dehydroepiandrosterone (DHEA) compared with TRIAC, DHEA or placebo alone on corticosteroid induced effect on collagen synthesis in humans. Six healthy male human volunteers aged 40-65 participated. Four areas of abdominal skin were pre-treated for 3 weeks with betamethasone valerate cream. The same areas were then treated with one of the following alternatives in the same cream vehicle: TRIAC, DHEA, TRIAC+DHEA and placebo for 2 weeks. Then suction blisters were raised in each of these areas with a vacuum pump. The blister fluid from each area was collected and frozen until analysis. Analysis of amino terminal propeptide of human type I procollagen (PINP) in suction blister fluid was performed using a commercially available immunoassay (Orion Diagnostics) kit. This study has for the first time shown that a combination of TRIAC and DHEA could effectively stimulate collagen synthesis in skin pretreated with betamethasone valerate demonstrated by an increase in PINP, and that the combination was more effective than TRIAC or DHEA alone. This combination could be used to effectively treat skin atrophy in corticosteroid induced skin atrophy. It could also be used to treat skin atrophy due to other circumstances such as e. g. sun damaged skin and skin atrophy due to high age. Another interesting application would be to combine TRIAC and DHEA with a potent corticosteroid in order to prevent corticosteroid induced skin atrophy. If this combination still is effective in the treatment of eczema and psoriasis and without the risk of skin atrophy this combination will be a major breakthrough for the use of potent topical corticosteroids.
