Darier disease and Hailey-Hailey disease are rare autosomal dominant genodermatoses that negatively impact patient quality of life. In addition, they pose challenges to dermatologists who manage these diseases. There is currently no treatment that reliably induces remission for either disease, leaving patients dependent on symptom management. Oral and topical retinoids are the most commonly used therapies but have numerous side effects that often lead to discontinuation or inability to tolerate long-term treatment (Burge and Wilkinson in J Am Acad Dermatol 27:40-50, 1992). Due to the rarity of these diseases, there are no clinical trials investigating treatment options for the persistent flares patients experience. In light of this, dermatologists have tried various methods used in the management of other inflammatory disorders including photodynamic therapy (PDT). A systematic review was conducted to investigate this treatment option which yielded a total of 12 studies that had reported the use of photodynamic therapy (PDT) as a treatment option for Darier or Hailey-Hailey disease. Though results showed that PDT can induce disease remission for up to several months or years, there are many unanswered questions that need to be addressed before adopting PDT as a leading treatment option for those genodermatoses. In particular, cost, tolerability, and efficacy and safety in patients who are skin of color need to be further studied. Lastly, recommendations on treatment duration, number of sessions, photosensitizing agents, lasers, and continuation or discontinuation of topical and systemic medications need to be appraised before formal recommendations can be made.