Inclusion Criteria:

• * A subject must meet all the following criteria to participate in the registry:
• 1. Has been diagnosed with GPP by a dermatologist or a qualified dermatology practitioner.
• 2. Is at least 18 years of age and has attained the legal age for consent to procedures involved in the research, under the applicable law of the jurisdiction in which the research is being conducted.
• 3. Is willing to provide consent for participation in the registry.
• 4. Is willing to provide Personal Information

Exclusion Criteria:

• * Any of the following would exclude the subject from participating in the registry:
• 1. Is participating or planning to participate in a blinded clinical trial evaluating a systemic agent for the treatment or prevention of flares related to GPP.
• 2. Is enrolled in another CorEvitas registry for a dermatological condition. Subjects enrolled in another CorEvitas registry must be exited to be eligible for enrollment into the GPP Registry