Combination topical appears effective for subclinical actinic keratosis treatment

A small study of actinic keratoses patients suggests 5-fluorouracil (5-FU) 0.5%/salicylic acid 10% is an effective field treatment for subclinical actinic keratoses lesions.

The importance of treating subclinical actinic keratosis is gaining support, according to the authors who are from Germany and Spain.

Successfully clearing the entire actinic keratosis field depends on having a treatment option that clears not only clinical but also subclinical lesions, according to the study’s senior author Eggert Stockfleth, M.D., professor and director of dermatology at Ruhr-University, Bochum, Germany.

“[Clearing subclinical actinic keratoses lesions] also means you will have low recurrence rates,” Dr. Stockfleth says.

The authors write that as far as they know this is the first randomized, vehicle-controlled study looking at 5-FU 0.5%/salicylic acid 10% treatment for subclinical actinic keratoses lesions. They conducted a subanalysis of a phase III study on the topical formulation, launched in Europe under the tradename Actikerall (Almirall), which showed 5-FU 0.5%/salicylic acid 10% was superior to diclofenac 3% gel in hyaluronic acid for actinic keratosis treatment.

The 27 patients in the subanalysis had at least three subclinical actinic keratoses lesions within a 25 cm2 skin area. The authors diagnosed subclinical lesions using reflectance confocal microscopy and treated 17 of the patients with 5-FU 0.5%/salicylic acid 10% once daily for 12 weeks. The other 10 patients were treated with vehicle. The authors evaluated subclinical actinic keratosis lesions at baseline; at weeks four, six and 12; and at eight weeks following the treatment’s end.

They found the average number of subclinical lesions decreased from 3.0 at baseline to 0.3 eight weeks following the end of treatment in the 5-FU 0.5%/salicylic acid 10% group. The 90 percent reduction of subclinical lesions in the treated group was compared to an average decrease from 3.0 lesions at baseline to 1.6, or a 47 percent reduction, in the vehicle arm.

And while 69 percent of preselected subclinical actinic keratosis lesions in the 5-FU 0.5%/salicylic acid 10% group were completely cleared, 40 percent of those lesions were cleared among the vehicles.

The researchers noted some patients had local erythema from treatment, which was also a finding in previous studies, according to Dr. Stockfleth.

While this study suggest clinical efficacy for 5-FU 0.5%/salicylic acid 10% treatment for subclinical actinic keratosis lesions, larger studies need to be done to confirm results, the authors write.

Dr. Stockfleth tells Dermatology Times that 5-FU 0.5%/salicylic acid 10% treatment is an option for all actinic keratosis patients, regardless of the number and density of clinical and subclinical lesions.

“This treatment should be considered as one of the first line treatments, especially in patients with multiple lesions within an area of 25 cm2,” Dr. Stockfleth says.

REFERENCES

Ulrich M, Reinhold U, Falqués M, et al. “Use of reflectance confocal microscopy to evaluate 5-fluorouracil 0.5%/salicylic acid 10% in the field-directed treatment of subclinical lesions of actinic keratosis: subanalysis of a Phase III, randomized, double-blind, vehicle-controlled trial,” J Eur Acad Dermatol Venereol. 2017 Sep 28. doi: 10.1111/jdv.14611.

Nguyen HP, Rivers JK. Actikerall™ (5-Fluorouracil 0.5% and Salicylic Acid 10%) “Topical Solution for Patient-directed Treatment of Actinic Keratoses,” Skin Therapy Lett. 2016 May. [NO DOI]