Clinical efficacy of bromocriptine and the influence of serum prolactin levels on disease severity in patients with chronic plaque-type psoriasis

Background : Psoriasis is a T-cell mediated hyperproliferative cutaneous disease of multifactorial etiology. Prolactin (PRL) has been implicated in the pathogenesis of psoriasis and several studies have pointed to a potential therapeutic role of bromocriptine in psoriasis. Aim: To assess the clinical efficacy of bromocriptine and the influence of serum prolactin levels on disease severity in patients with chronic plaque-type psoriasis. Methods: Forty-five patients with chronic plaque-type psoriasis and 45 healthy control subjects were included in the study. The patients were divided into three equal groups; a group treated with narrow-band ultraviolet B (NB-UVB), a group treated with bromocriptine, and a group treated with both NB-UVB and bromocriptine. Serum PRL levels and psoriasis area severity index (PASI) scores were measured before and after a 12-week treatment period. Results: There was no significant difference in the serum PRL levels between the patients prior to treatment and the controls. Correlations between PASI scores and serum PRL levels before and after treatment  were insignificant. Post-treatment PASI scores were significantly lower than pretreatment values in each of the treated groups. Post-treatment serum PRL levels were significantly lower in both groups receiving bromocriptine than the group receiving NB-UVB alone, they were also significantly lower in the group treated with NB-UVB and bromocriptine than the group treated with bromocriptine alone. Conclusions: Bromocriptine may be of value in the treatment of chronic plaque-type psoriasis in the absence of hyperprolactinemia. NB-UVB may have an additive effect to bromocriptine on serum PRL levels. Keywords: Bromocriptine; Psoriasis; Prolactin