Inclusion criteria  Biopsy proven cutaneous mastocytosis with or without evidence of systemic disease Male and female patients 18 to 80 years of age No UVB treatment of the skin for 6 months prior to study entry No use of topical or systemic corticosteroids for 1 month prior to study entry Good general health as confirmed by medical history Female patients of child-bearing potential with negative urine pregnancy test who agree to use effective methods of birth control or remain abstinent during treatment. Participants must use birth control for the entire study and for at least 1 week after the last application of the study formulation. Acceptable methods of birth control include ongoing hormonal contraception methods, (such as birth control pills, patches, injections, vaginal ring, or implants), barrier methods (such as a condom (for men) or diaphragm used with a spermicide), intrauterine devices, tubal ligation, or abstinence. Patients who are willing and capable of cooperating to the extent and degree required by the protocol; and Patients who read and sign an approved informed consent for this study  Exclusion criteria  Vulnerable study population Exposure to ultraviolet B (UVB) radiation to any region of the skin surface for 6 months  Regular use of skin lightening agents within 1 month of study entry, including  Topical corticosteroids Topical bleaching products Topical retinoids  Use of systemic preparations within 1 month of study entry, including:  Systemic corticosteroids Systemic cyclosporine, interferon Systemic acitretin, etretinate, isoretinoin Systemic methotrexate, Systemic photoallergic, phototoxic and/or photosensitizing drugs UV light therapy and sunbathing Inability to communicate or cooperate with the Principal Investigator and/or Investigators due to language problems, poor mental development or impaired cerebral function Pregnant or nursing women Women planning a pregnancy within the study period