Alacare® patches are a novel treatment option for mild to moderate actinic keratoses on the face and scalp. Actinic keratoses, also known as solar keratoses, are scaly lesions caused by ultraviolet radiation. If left untreated, a small proportion of these lesions may develop into squamous cell carcinomas.
Alacare® patches contain 5-aminolevulinic acid (5-ALA), a precursor to the photosensitising agent, protoporphyrin IX (PPIX). PPIX is normally converted to haem. However, when 5-ALA is administered exogenously, the enzyme that catalyses this conversion becomes saturated leading to intracellular accumulation of PPIX. Exposure of the treated lesions to narrow band red LED light activates PPIX. Reactive oxygen species are generated, and cellular damage occurs. This therapy is relatively selective for abnormal tissue as PPIX is known to accumulate preferentially in cancerous and precancerous cells.
For thin actinic keratosis lesions on the face and scalp, meta-analyses demonstrate a 14% greater clearance rate for photodynamic therapy compared to cryotherapy. Up to eight Alacare® patches may be applied to a patient at a time ensuring that each patch covers the lesion completely. The patches are worn for four hours and then removed before light therapy commences. Erythema, exfoliation, pain, and pruritus are very common adverse effects. These effects are usually mild to moderate and only result in early termination of illumination in 1% of patients.
- Alacare® (5-aminolevulinic acid) Australian approved product information. Warriewood: Link Medical Products. Approved February 2016.
- Patel G, Armstrong AW, Eisen DB. Efficacy of photodynamic therapy vs other interventions in randomized clinical trials for the treatment of actinic keratoses: a systematic review and meta-analysis. JAMA Dermatol. 2014; 150(12): 1281-8.
- Wachowska M, Muchowicz A, Firzuk M, Gabrysiak M, Winiarska M, Wanczyk M, et al. Aminolevulinic acid (ALA) as a prodrug in photodynamic therapy of cancer. Molecules 2011; 16: 4140-64.