Topical Treatments for Keratosis Pilaris

What Is Keratosis Pilaris?

Keratosis pilaris is a skin condition characterized by the appearance of follicular hyperkeratotic, erythematous papules most frequently seen on the extensor surfaces of the proximal extremities.¹ It can also less commonly affect the trunk, distal extremities, and lateral cheeks.¹ It affects 50 to 80 percent of adolescents and approximately 40 percent of the adult population.¹

Although it is commonly seen, its exact etiology and pathophysiology are unknown. It is thought that keratosis pilaris may be a result of a loss of normal epithelial barrier function, as supported by the condition’s association with atopic dermatitis and mutations in the filaggrin gene.¹ Furthermore, the most widely accepted theory of its pathophysiology proposes that abnormal follicular epithelial keratinization causes an infundibular plug to form, leading to erythema and scaling around the follicle opening.¹

Keratosis pilaris is asymptomatic and often improves over time, but treatment may be pursued to improve the skin’s cosmetic appearance and alleviate psychological distress.¹ The condition has no known cure, and is often difficult to treat due to the limited efficacy of currently available therapies.¹ The most widely available existing topical treatments include emollients, keratolytic agents, and retinoids.²

What Is Used to Treat Keratosis Pilaris?

The most commonly used interventions to treat keratosis pilaris are:

• Keratolytic agents
• Emollients
• Topical retinoids
• Laser therapy

Keratolytic Agents

Topical keratolytic agents are among the first line treatments for keratosis pilaris.¹ These agents facilitate the breakdown and desquamation of keratinized cells in the stratum corneum and can improve the skin’s texture.³ Keratolytics include compounds such as salicylic acid, lactic acid, urea, alpha hydroxy acid, beta hydroxy acid, and propylene glycol.²

A randomized clinical study compared the efficacy, safety, hydrating properties, and tolerability of lactic acid and salicylic acid topical creams in the treatment of keratosis pilaris.³ Patients applied either 10% lactic acid or 5% salicylic acid creams twice daily for 3 months.³ Both treatments showed a significant reduction of lesions at the end of 4, 8, and 12 weeks of treatment, with a mean percentage of reduction from baseline of 66% in the lactic acid group and 52% in the salicylic acid group.³ Mild irritation of the skin with a burning or itching sensation was the only adverse side effect reported in the study, and it was seen more frequently in the lactic acid group.³ Skin conductance also became significantly higher after treatment with both agents, reflecting an improved state of hydration of the skin’s surface.³ The study concluded that 10% lactic acid cream improves skin texture by stimulating cell growth towards the skin surface and providing outer skin hydration at a slower pace, while 5% salicylic acid cream improves hydration by directly removing the upper surface layer of dead cells, softening the skin.³

Emollients

Often used in conjunction with keratolytics, emollients are an additional first line treatment for keratosis pilaris.¹ They include creams, ointments, and moisturizers, and help to maintain hydration of the skin while reducing flaking.⁴ The American Academy of Dermatology recommends that patients with keratosis pilaris apply moisturizer after every shower or bath, within 5 minutes of getting out of the bath or shower while the skin is still damp, and at least 2 or 3 times a day.² Many of the moisturizing creams used to treat keratosis pilaris contain urea or lactic acid.² Furthermore, a study of 30 patients demonstrated the efficacy of Aquaphor ointment in improving the appearance of keratosis pilaris in pediatric patients.⁵ Aquaphor is an inexpensive topical emollient and was shown to improve the clinical findings of keratosis pilaris in 78% of patients after 4 weeks of use.⁵

Topical Retinoids

Topical retinoids, such as tazarotene, selectively transactivate the retinoic acid receptors of the skin.⁶ This mechanism modulates keratinocyte differentiation through an antiproliferative effect.⁶ Topical retinoids can thus have a role in controlling the hyperkeratotic lesions seen in keratosis pilaris. A 2002 study demonstrated the efficacy of topical retinoids in reducing or resolving the lesions of keratosis pilaris.⁶ 20 patients with keratosis pilaris applied an oil-in-water emulsion containing 0.01% tazarotene daily for 4 to 8 weeks.⁶ The lesions began to gradually fade in 2 weeks, and resolved after 4 to 8 weeks.⁶ Topical retinoids are typically a second line treatment used if a patient has had no response to a trial of treatment with emollients and topical keratolytics.¹

Laser Therapy

Laser therapy has also been shown to have efficacy in improving the cosmetic appearance of keratosis pilaris in patients with lesions refractory to treatment with other topical methods.¹ Types of lasers that may be used include pulsed dye laser, alexandrite laser, Nd:YAG laser, and fractional CO2 laser treatments.¹ Laser therapy has been shown to be effective in decreasing skin hyperpigmentation and roughness and is easily accessible and safe.⁷

Practical Tips

• Although keratosis pilaris is asymptomatic, the cosmetic appearance of lesions can result in psychological distress in affected patients
• Keratosis pilaris is often refractory to treatment, but topical retinoids, keratolytic agents, emollients, and laser therapy have been shown to improve clinical findings in some patients
• In many cases, keratosis pilaris will resolve on its own over time