Clinical Trial of 4% Niacinamide Versus 0.05% Desonide for the Treatment of Axillar Hyperpigmentation

• Inflammation [ Time Frame: 9 weeks ] [ Designated as safety issue: No ]
  Quantification of inflammatory infiltrate in skin biopsies by histologic lymphocites infiltrate and immunohistochemistry stain anti-CD1
• Trauma [ Time Frame: 9 weeks ] [ Designated as safety issue: No ]
  To detect trauma we measure damage in Membrane Basal by anti-collagen IV immunohistochemistry stain
• Change in transepidermal water loss in hyperpigmented lesion [ Time Frame: 9 weeks ] [ Designated as safety issue: No ]
  Quantification of water loss measured by a evaporimeter in grams per squared meter per hour. Is an indirect measure of inflammation.
• Investigator's Depigmentation Improvement [ Time Frame: 9 weeks ] [ Designated as safety issue: No ]
  Clinical improvement is assessed by means of digital photographic registration (frontal, right, and left views). Two independent observers clinically graded the global improvement as poor (0-25%), mild (26-50%), good (51-75%), and excellent (>75%).

Axillary hyperpigmentation is a frequent consultation in dark skin populations although its exact prevalency is unknown. Currently, there are not studies about physiopathology and treatment for this entity. The objective is to evaluate the depigmenting effect of topical 4% niacinamide versus 0.05% desonide in axillary hyperpigmentation.

At least 30 axillas with hyperpigmentation in individuals of phototype III-V, aged 18-50 years are going to be randomly assigned to receive niacinamide, desonide or placebo daily. No hygienic habits will not be modified. Volunteers will be evaluated at baseline and for 9 weeks, by means of histological, histochemical and immunohistochemistry analysis, as well as Transepidermal Water Loss (TEWL), colorimetry, clinically and by photography control.

Axillary hyperpigmentation is frequent in dark skin population, is possible a type of postinflammatory hyperpigmentation present in phototypes IV to VI. Previous reports have described increased intensity of Masson-Fontana, anti-tyrosinase and/or anti-TRP1 staining, indicative of melanocyte stimulation and increased melanin production, but the exact mechanism is unknown. The hair plucking, the rubbing of clothes on skin and physical stimulation from washing and drying the underarm are factors implicated. The objective of our study is evaluate the depigmenting effect of topical niacinamide versus desonide in axillary hyperpigmentation through the histochemistry and immunohistochemistry staining.

The study population will include at least 30 axillas with hyperpigmentation in a population with phototype III-V and aged 18-50 years old. Informed consent will be obtained from the patients, under approval by the local ethical committee (Institutional Review Board). The patients are going to be randomly assigned to receive 4% niacinamide, 0.05% desonide or placebo daily once at night. None hygienic habit is going to be modified. Volunteers will be evaluated at baseline and 9 weeks later, with histochemical and immunohistochemical analysis (biopsies), colorimetric value axis L*, a*, b* (Chromameter CR-300, Minolta, Osaka, Japan), Transepidermal Water Loss (TEWL) by means of an evaporimeter (Dermalab, Cortex Technology, Denmark), clinical assessment and photography control.

Statistical analysis was performed using t student, the level of significance was set at 5%. And clinical evaluation will be analysed by means of chi square test.

• Drug: Desonide
  Once-a-day applying on axillar hyperpigmentation for 9 weeks
  Other Name: 0.05% Desowen cream, Galderma, France.
• Drug: Niacinamide
  Once-a-day applying on axillar hyperpigmentation for 9 weeks
  Other Name: Nicotinamide, nicomide
• Drug: Placebo
  Humectant placebo cream
  Other Name: vanicream, cetaphil

• Active Comparator: Niacinamide
  4% niacinamide cream that will be randomly applied on axillar hyperpigmentation once-a-day for 9 weeks.
  Intervention: Drug: Niacinamide
• Active Comparator: Desonide
  Once-a-day application of 0.05% desonide cream on axillar hyperpigmentation
  Intervention: Drug: Desonide
• Placebo Comparator: Placebo
  Humectant placebo cream
  Intervention: Drug: Placebo

• Navarrete-Solís J, Castanedo-Cázares JP, Torres-Álvarez B, Oros-Ovalle C, Fuentes-Ahumada C, González FJ, Martínez-Ramírez JD, Moncada B. A Double-Blind, Randomized Clinical Trial of Niacinamide 4% versus Hydroquinone 4% in the Treatment of Melasma. Dermatol Res Pract. 2011;2011:379173. Epub 2011 Jul 21.
• Torres-Álvarez B, Mesa-Garza IG, Castanedo-Cázares JP, Fuentes-Ahumada C, Oros-Ovalle C, Navarrete-Solis J, Moncada B. Histochemical and immunohistochemical study in melasma: evidence of damage in the basal membrane. Am J Dermatopathol. 2011 May;33(3):291-5.

Inclusion Criteria:

• Women over 18 years old
• Healthy
• Clinical diagnosis of axillar hyperpigmentation

Exclusion Criteria:

• Pregnancy or lactation
• Obesity
• Endocrinological diseases
• Mental diseases
• Treatment for axillar hyperpigmentation in the last 2 months