The purpose of this study is to determine whether 5-FU infusion (Microinfusion of Medicine Percutaneously - MMP) is effective for Idiopathic Guttate Hypomelanosis (IGH) repigmentation compared to conventional Microneedling. MMP is a procedure done with tattoo devices using medication in place of ink.

Split body design. Each upper limb will receive a different intervention (experimental or placebo)

Inclusion Criteria:

• Healthy males and females, between ages 30 and 70
• Photodamaged skin on upper limbs with IGH lesions meeting aforementioned criteria and excluding differential diagnosis
• Fitzpatrick skin types III - V
• Apt and willing to comply with the entire program as well as appointments, treatment and examination
• Capable of understanding and providing a written informed consent
• Fertile women will have to use a viable birth control method for at least 3 months prior to entry and throughout the entire study

Exclusion Criteria:

• Pregnancy, intention to become pregnant during the course of the study, less than 3 months after delivery or less than 6 weeks after breastfeeding cessation.
• Uncontrolled comorbidity or any disease that, in the investigator's opinion, may interfere with the treatment, healing or cure.
• Present symptoms of hormonal disturbances, as per the investigator's criteria.
• Constitutional photosensitivity or due to metabolic disfunction, or due to use of external agentes (pharmaco, natural products, etc.) prior to initial treatment or during the study.
• Use of oral isotretinoin 6 months prior to initial treatment or during the course of the study.
• Prior treatment in target área 3 months prior to initial treatment or during the course of the study.
• Adverse reaction to any external agentes (gel, lotions or anesthetic creams) required during the study in case no alternative is available for such agent.
• History of keloids or other type of hypertrophic scar formation or poor wound healing in a previously injured area of skin.
• History of collagen disease.
• Displastic nevus or suspicious carcinogenic lesion in área to be treated.
• Hemmorragic disorder or under anticoagulant medication, including the use of aspirin not permitting a minimum 10-day suspension prior to each treatment period (in accordance with the criteria of the patient's physician).
• Skin frailty of sensitivity, favoring hemmorrage.
• History of immunosuppresion / immunological deficiency disorders (including HIV infection) or use of immunosuppressant medication.
• Participation in a study involving medication or another device three months prior to the study or during enrollment herein.
• Any condition which, in the investigator's opinion, would jeopardize the study or its participants, such as acute psychiatric disorders, panic syndrome or any aversion to needles or to the procedure.
• Hypochromiant dermatoses such as vitiligo, pitiriasis, versicolor, albinism.
• Dermatoses that evolve like Koebner's phenomenon.
• Cutaneous infectious process at the application site.