Incontinentia pigmenti (IP), or Bloch-Sulzberger syndrome, is a rare X-linked dominant genodermatosis primarily affecting females. Although IP affects many organ systems, the hallmark feature of this disease is its characteristic cutaneous eruption along the lines of Blaschko that evolves through four distinct stages: inflammatory/vesiculobullous, verrucous, hyperpigmented and hypopigmented/ atrophic. We describe a case of IP in its vesicular stage that completely resolved with topical Protopic (tacrolimus) 0.1% ointment. The treatment successfully halted the progression of disease through its subsequent disfiguring stages.