Journal of Clinical and Aesthetic Dermatology

Psoriasis and Cutaneous Supplement 2016

An evidence-based, peer-reviewed journal for practicing clinicians in the field of dermatology

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Page 24 of 35

of "in-office painless PDT." The protocol requires that the patient apply ALA to the affected areas of the face or scalp and incubate it for 15 minutes. After the 15- minute incubation period expires, the patient is exposed to blue light for 60 minutes. The standard in- clinic PDT-ALA treatment is generally performed using 1 to 3 hours of ALA incubation followed by 16 minutes and 45 seconds of blue light exposure. These two in- clinic PDT protocols were tested in three patients using the "split face" approach. Half of the face was treated using the 15 minute ALA/60 minute blue light treatment and the other half was treated with 75 minute ALA/16 minute and 45 seconds blue light. Study results are reported in Table 9. Painless PDT can be reproduced in the clinic. Update on the Safety of Ingenol Mebutate Ingenol mebutate (Picato ® , Leo Pharma, Inc.) was the subject of an FDA Drug Safety Communication on August 21, 2015. This type of statement from the FDA announces future changes to product labeling and is not a "black box warning." 135 The FDA warned about the possibility of severe adverse events associated with application of ingenol mebutate (IM), specifically severe allergic reactions, herpes zoster, and severe eye injuries. These events are very rare. Based on one million patients, severe allergic reactions were reported in about five, and both herpes zoster and eye injuries in fewer than 20 each. Safety Communications are published relatively frequently with the FDA issuing about 400 to 500 of them annually. It should be noted that the other agents that treat field AK have previously been the subject of such communications. 136 Safety Communications improve drug safety by providing clinicians with relevant advice for their practice. Delving Deeper: Clinically Evident and Subclinical Lesions Skin cancer is one of the most frequently occurring forms of malignancy around the world. Risk factors for skin cancer are well known. Human papillomaviruses (HPV) can infect the cutaneous and mucosal epithelia, resulting in lesions. 137 About 15 percent of all cancerous tumors are caused by viruses, with nonmelanoma skin cancer (NMSC) correlating with HPV infection. 138 Ultraviolet (UV) radiation from the sun can damage cells and is another risk factor for NMSC, which includes basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). When a noninfected cutaneous cell is exposed to UV radiation, cell damage is either repaired (resulting in a normal phenotype) or if the damage cannot be repaired, the cell undergoes apoptosis (killing the abnormal phenotype). If the UV radiation affects an HPV- positive cell, no repair or programmed cell death can be initiated, with the result that cells with the abnormal phenotype proliferate and accumulate, resulting in skin cancer. It is believed that homeodomain-interacting protein kinase 2 (HIPK2) can suppress tumorigenesis in the skin and regulates apoptosis through interactions with tumor-suppressor p53, in that it mediates p53 phosphorylation at Ser46 and, in that way, promotes the expression of pro-apoptotic genes. 139 In the case of field cancerization, at any given point in time, the cascade is at different stages at multiple sites over the region of sun-exposed skin. This means that the clinician must treat early AK, AK, and SCC, sometimes in close proximity to each other. AK affects about 58 million Americans and has a prevalence of 11 to 25 percent in the Northern Hemisphere. 140 While NMSC is not a public health threat in terms of mortality, it is associated with high costs and a substantial burden to the healthcare system. NMSC prevalence increases with age, so the U pdates on Psoriasis and Cutaneous Oncology: Proceedings from the 2016 MauiDerm Meeting [ S E P T E M B E R 2 0 1 6 • V O L U M E 9 • N U M B E R 9 ] S U P P L E M E N T T O T H E J O U R N A L O F C L I N I C A L A N D A E S T H E T I C D E R M AT O L O G Y S 2 1 TABLE 9. Split-face study (n=3) for field actinic keratosis (AK) on the face and neck using two "in-clinic" painless photodynamic therapy (PDT) protocols. In this study, pain was rated from 0 (no pain at all) to 5 (worst pain imaginable) PROTOCOL DESCRIPTION AK COUNT PERCENTAGE REDUCTION IN AKS AVERAGE PAIN SCORE AT BASELINE POST-TREATMENT Painless PDT 15 min amino- levulinic acid incubation then 60 minutes blue light 27 13 52% 0/5 (range 0–0) Standard PDT 75 min amino- levulinic acid incubation then 16 minutes 45 seconds blue light 32 18 44% 3.5/5 (range 3–4)

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