This study evaluates the safety and efficacy of PTX-022, topical rapamycin, in the treatment of adults with moderate to severe Pachyonychia Congenita.

This study includes four-parts, and if a participant completes all parts, the participant will have received at least 3-months of PTX-022 treatment.

Inclusion Criteria:

• Adult patients, 18 years or older
• Diagnosed Pachyonychia Congenita (PC), genetically confirmed
• Moderate to Severe PC
• Able and willing to comply with all protocol-required activities
• Willing and able to provide written informed consent

Exclusion Criteria:

• Any significant concurrent condition (including involving the inferior to the ankle) that could adversely affect participation.
• Any intentional changes in the patient's daily activities (associated with standing, walking and keeping balance), not resulting from an improvement in the patient's condition due to treatment.
• Patient's deemed by the investigator as unwilling or unable to remain compliant with all tests and procedures, including adherence to study drug administration and other protocol-required activities.

During the open-label period, there is no masking. During the randomized, double-blind, placebo-controlled period the participant and Investigator are masked.