The primary objective of this study is to evaluate the long term safety and tolerability of diacerein 1% ointment for 2 treatment cycles in subjects with EBS that previously participated in the CCP-020-301 or the CCP-020-101 studies.

This is an international, multicenter, open-label, long term extension study evaluating the safety of topical Diacerein 1% Ointment for the treatment of subjects with EBS. At Visit 1, EBS subjects who completed the CCP-020-301 double-blind safety and efficacy study or participated in the CCP-020-101 PK study (feeder studies) who meet all the inclusion/exclusion criteria will be eligible to complete 2 treatment cycles of CCP-020.

Each treatment cycle will consist of 8 weeks on treatment (once-daily, at home study medication applications) followed by 8 weeks off treatment (only Investigator approved bland, non-medicated emollient/moisturizer, routine cleansing products and sunscreens) with a maximum of 2 treatment cycles allowed for up to 52 weeks.

At Baseline Visit (corresponding to the final study visit of the feeder study), the investigator will perform a clinical assessment and determine if any of the subject's lesions require treatment (up to 30% BSA). If the subject has active lesions as determined by the Investigator's clinical assessment, the subject will initiate a cycle of once-daily, at home study medication application to their EBS lesions for 8 weeks (treatment period) followed by an 8-week period where no treatment will be administered. Subjects presenting with no active lesions (as determined by the Investigator's clinical assessment) will not begin treatment and instead, will be instructed to return to the clinic for re-evaluation in 8 weeks or upon worsening of EBS lesions, whichever happens first.

Key Inclusion Criteria:

• The subject is capable of understanding and complying with protocol requirements.
• The subject or the subject's legally acceptable representative signs and dates a written, informed consent/assent form and any required privacy authorization prior to the initiation of any study procedures.
• Subject has a documented genetic mutation consistent with EBS.
• Subject has completed study CCP-020-301 or participated in study CCP-020-101.
• Subject/caregiver agrees to report use of any topical therapies applied to EBS lesions
• If the subject is a woman of childbearing potential, she has a negative urine pregnancy test and agrees to use an approved effective method of birth control, for the duration of the study.
• Subject is non-lactating and is not planning for pregnancy during the study period.
• Subject is willing and able to follow all study instructions and to attend all study visits.

Key Exclusion Criteria:

• Subject has EBS lesions to be treated that are infected
• Subject has evidence of a systemic infection or has used systemic antibiotics within 7 days prior to Baseline Visit.
• The subject was discontinued from the feeder study due to an adverse event judged to be related or possibly related to the study medication.
• Subject has experienced a change in clinical status from the feeder study that puts the subject at undue risk to participate.

Each treatment cycle will consist of 8 weeks on treatment, followed by 8 weeks off treatment with a maximum of 2 treatment cycles allowed for up to 1 year. Subjects should be assessed at minimum every 8 weeks for disease activity. Once a subject completes two cycles of treatment or reaches Week 52, the subject will be discharged from the study. Subjects may not start a new treatment cycle past Week 36 from Baseline Visit without prior sponsor approval. The duration of a subject's participation in the extension study may be as short as 32 weeks or as long as 52 weeks depending on the cycle initiation schedule for each individual subject.