The purpose of this prospective, randomized, controlled, single-blinded investigation is to study the efficacy, tolerability and safety of azelaic acid iontophoresis (AAI) versus topical treatment with azelaic acid cream in female patients with melasma.

Patients will be randomized and allocated in concealed manner to one of the two treatment arms: AAI or topical azelaic acid cream.

Azelaic acid iontophoresis treatment schedule:

Patients randomized to the AAI group will receive iontophoresis with 15% azelaic acid twice weekly over a period of 12 weeks.

Azelaic acid topical treatment schedule:

Patients randomized to the topical treatment group will receive topical treatment with 20% azelaic acid cream twice daily over a period of 12 weeks.

Besides emollients no additional specific treatments will be allowed during the study.

The use of broad spectrum (UVA+UVB) sunscreen is recommended over the entire study period (9 month).

Follow-up period:

After completion of the active study period (3 month in both treatment groups), maintenance and efficacy of both treatment schedules will be followed up quarterly over 6 month

Inclusion Criteria:

• Woman
• MASI - Score over 6
• Age: over 18 years
• Skin Type: III, IV, V

Exclusion Criteria:

• Skin Type: I, II, VI
• Pregnant or lactating women
• Local therapy of intent-to-treat area within the last 6 month
• Patient with a pacemaker or metal implant
• Epileptic
• Mental incompetence to understand the protocol
• Known allergic reactions to one of used substances
• Serious encroachment on physical condition