| Regime | Indication | Complications/ Tips on treatment | Success rate | |
|---|---|---|---|---|
| Cryosurgery (liquid nitrogen) as a lesion-directed treatmenta | Single cycle | Effective on all sites and all grades of AK without field change. Particularly effective for hyperkeratotic AK. | Soreness, blistering, hair loss, scarring, infection, and pigmentary skin changes.Caution - Slow healing and ulceration are possible below the knee, on the scalp, or on the pinna especially in older patients.Caution – Can be difficult to use near mouth and eyes. | 39%–88% |
| Photodynamic therapy (PDT) as a lesion-directed or field treatment | Photosensitising topical cream/gel applied under occlusion followed by illumination of the treatment field with a laser or non-laser light (eg, blue light or red light; conventional PDT or natural sunlight; daylight PDT). | Conventional PDT – suitable for Grade 2 and 3 AK with or without field change.Daylight PDT – suitable for extensive grade 1 AK with field change.Only available in secondary care. | Pain, initial erythema, burning sensation and crusting followed by pigmentary change and ulceration.Tip - Suitable for scalp and below knee lesions with a lesser risk of causing poor wound healing as compared to cryosurgery and 5-Flurouracil. | 69%–93% |
| Skin surgeryb as a lesion directed treatment | Curette and cautery (2 cycles) or excision biopsy. | If diagnosis uncertain, histology is required, large keratin horns, grade 3 AK and AK resistant to therapies listed in Table 1. | Infection, bleeding, scarring, poor wound healing and pain.Caution - Slow healing and ulceration are possible below the knee especially in elderly patients. | No clinical trials |
Photodynamic therapy is performed in secondary care. Skin surgery and cryosurgery can be performed by GPs with prior training. a5 seconds of total treatment time achieves a 39% cure rate and over 20 seconds of total treatment time achieves 83% cure rate. bElectrodessication and curettage provides 95–99% clearance for lesion-directed therapy for hyperkeratotoic AK as other therapies cannot penetrate as deep as electrodessication and curettage.