Combined trichloroacetic acid peel and topical ascorbic acid versus trichloroacetic acid peel alone in the treatment of melasma: a comparative study.

BACKGROUND: Melasma is a common acquired hypermelanosis that is difficult to treat. Several chemical peeling agents were used in treatment of melasma. Topical vitamin C was also used with minimal side effects. AIM: To compare the effect of 20% trichloroacetic acid (TCA) peel alone vs. 20% TCA peel combined with topical 5% ascorbic acid in cases of epidermal melasma. PATIENTS AND METHODS: Thirty women with bilateral epidermal melasma (Fitzpatrick skin types III and IV) were divided into two groups (A and B, 15 patients each). Before therapy, digital photography and a melasma area and severity index (MASI) score were done for each patient. Groups A and B were primed for 2 weeks before TCA peel. Group B also applied 5% ascorbic acid topically once daily; 20% TCA peel was done for all patients weekly until clearance of melasma or for a maximum of six peels. Group B continued to use 5% ascorbic acid topically in between peels and during the 16-week follow-up period. Patients were assessed at the end of peeling sessions and at the end of follow-up by photography, MASI score, and a global evaluation by the patient. RESULTS: Group B compared with group A showed a significant decrease in MASI score at the end of TCA peels (P < 0.001) and at the end of the 16-week follow-up period (P < 0.003). Global evaluation showed that 13 patients (87%) in group B improved or maintained their improvement compared with only 10 patients (67%) in group A. CONCLUSION: Topical ascorbic acid combined with 20% TCA peel in melasma improves the results and helps in maintaining the response to therapy.

Expression of nerve growth factor and its high-affinity receptor, tyrosine kinase A proteins, in the human scalp skin.

BACKGROUND: Nerve growth factor (NGF) and its high-affinity receptor, tyrosine kinase A (TrkA), are members of the neurotrophin family. NGF-TrkA are involved in murine hair morphogenesis and cycling. To date, their expression in human hair follicle (HF) is unknown. In this investigation, we hypothesize that NGF-TrkA proteins are expressed in the human scalp skin. Moreover, NGF-TrkA expression in HF changes with the transitions from anagen-->>catagen-->>telogen stages. MATERIALS AND METHODS: To test our hypothesis and to fill this existing gap in literature, the immunostaining values (semiquantitative evaluation of protein expression: SI, staining intensity; PP, percentage of positive cells; and IR score, immunoreactivity score) of NGF and TrkA proteins were examined in human scalp skin by immunofluorescent and immunoperoxidase staining methods. Fifty normal human scalp skin biopsy specimens were examined (healthy females, 53-57 years). In each case, 50 HFs were analyzed (35, 10, and five follicles in anagen, catagen, and telogen, respectively). RESULTS: The IR scores were statistically significantly higher (p < 0.001) in anagen as compared with either catagen or telogen HF (9.61 +/- 0.12 vs. 1.4 +/- 0.10 vs. 0.6 +/- 0.10 for NGF and 3.31 +/- 0.02 vs. 0.5 +/- 0.10 vs. 0.2 +/- 0.10 for TrkA). In the anagen HF, high expression values were seen in the distal region, followed by upper distal, lower distal, and bulb regions for both NGF (10.6 +/- 0.21 vs. 10.3 +/- 0.21 vs. 9.2 +/- 0.40 vs. 8.1 +/- 0.30) and TrkA (3.54 +/- 0.07 vs. 3.45 +/- 0.07 vs. 3.31 +/- 0.06 vs. 3.13 +/- 0.04). Both NGF and TrkA proteins showed prominent expression in the melanocytes (7.6 +/- 0.15 vs. 2.50 +/- 0.07), keratinocytes (10.2 +/- 0.40 vs. 2.71 +/- 0.06), sebaceous glands (10.2 +/- 0.40 vs. 2.72 +/- 0.06), and sweat glands (10.4 +/- 0.40 vs. 2.84 +/- 0.05). CONCLUSIONS: Our findings report, for the first time, the expression pattern of NGF and TrkA proteins in human scalp skin and HF. The differential expression of these proteins during HF cycling suggests their possible roles in human HF biology. The clinical ramifications of these observations mandate further investigations.