Update on Topical Approaches for Managing Scalp Psoriasis

G. E. Searles, MD, FRCPC, FACP

Associate Clinical Professor (Medicine), Division of Dermatology and Cutaneous Sciences, University of Alberta, Edmonton, AB, Canada

Introduction

Patients suffering from scalp psoriasis frequently seek medical care because of the persistent discomfort and social embarrassment caused by the visible flakes that are shed onto clothing. However, the presence of hair makes it challenging to apply medication to the scalp. In addition, available therapies often do not facilitate ease of use and produce irritation and cosmetically unpleasant effects that can discourage patient adherence. Such therapeutic challenges often impede patients from deriving the full benefits from prescribed treatments. This article explores some of the current and new advances in the topical management of this common skin disorder and offers strategies that may improve treatment outcomes.

Diagnosis

• Psoriasis can be limited to the scalp, but it frequently involves more than one area of the body.
• Common concurrently affected sites include elbows, knees, buttocks, fingers, and nails.
• Between 50%-80% of all psoriasis patients have scalp involvement at some stage of their condition.¹
• The scalp may be the first site to show psoriasis; these lesions usually persist longer than those appearing elsewhere on the body.
• Psoriasis presents as well demarcated plaques that are characterized by scaling and erythema. Patients can experience varying degrees of itching and flaking.
• Patches are commonly located on the occipital scalp, over the ears, and along the frontal hairline.
• Seborrheic dermatitis can mimic psoriasis, but it tends to be more diffuse, less scaly, and has a more waxy texture. It can also spread down the forehead, and involve the nasolabial folds and eyebrows.
• Psoriatic scales are generally thicker, drier in appearance, and skin may crack and bleed.
• Scalp psoriasis can coexist with seborrheic dermatitis, and the persistence of yeast organisms in both conditions may share similar etiologies, although a skin culture is rarely helpful.
• Tinea or fungal infections frequently involve the hair shaft, leading to hair breakage, scaling, and swollen lymph nodes in the posterior cervical chain. It is more prevalent in children.

Therapeutic Considerations

• The presence of hair and scale build-up can interfere with medications reaching the scalp.
• Initial and maintenance strategies aimed at reducing thickened scales may be required for medications to effectively penetrate the scalp.
• Certain vehicles, such as ointments and creams, can be messy to apply and adhere to the hair shaft, resulting in a greasy appearance and prompting more frequent hair-washing. In addition, it is possible that insufficient quantities of the drug actually reach the scalp, which can render the treatment ineffective.
• Poor adherence can result from issues surrounding cosmetic acceptability, which leads to loss of effect and patient dissatisfaction with the treatment.
• Convenient and/or simplified dosing can improve medication adherence.
  • A study involving psoriasis patients demonstrated substantially higher rates of adherence with once-daily dosing (83%) vs. a twice-daily regimen (44%).²

   

• The vehicle can be as important as the active agent in achieving efficacy, tolerability, and treatment adherence.
  • Vehicles significantly impact the penetration and potency of active ingredients – with lotions, gels and foams being superior to creams and ointments.
  • Alcohol-based solutions can cause stinging and irritation.
  • Future management may include optimized vehicles (e.g., quick-break gel or foam, or lotions).

Topical Treatment Options for Scalp Psoriasis

When compared with phototherapy and medicated shampoos, topical agents are most commonly prescribed for scalp psoriasis. Although there is a broad range of topical therapies, factors that can limit treatment options include irritation, convenience, ease of application, cosmetic acceptability, effectiveness for reducing itch and scale, and safety for prolonged use without loss of benefit. A therapeutic approach that addresses as many of these variables as possible will improve treatment outcomes.

Tar

• Tar compounds slow the proliferation of skin cells and reduce inflammation, itching, and scaling.
• Following treatment, the agent should be removed using any mild, unmedicated shampoo.
• Acceptance by patients is limited due to irritation, staining, and tar’s odiferous quality.
• These compounds can cause folliculitis.
• There is concern that tar may be carcinogenic.

Corticosteroids

• Potent and ultrapotent corticosteroids (e.g., betamethasone dipropionate, clobetasol propionate) are widely used for their anti-inflammatory, immunosuppressive, and antiproliferative properties.
• They are commonly available as solutions, lotions, gels, and shampoos in a range of potencies.
• Corticosteroids can include keratolytic agents like salicylic acid.
• Prolonged use can result in tachyphylaxis.

Vitamin D3 Analogues (Calcipotriol/Calcipotriene)

• Calcipotriol promotes normal keratinization, supresses inflammatory responses, and modulates both epidermal proliferation and differentiation.
• They are available as solution or gel formulations.
• There is no loss of effect with prolonged use.
• They are helpful for reducing scaling, but their usefulness for controlling erythema and itch is limited.
• To avoid the potential effects on calcium metabolism, limit use to 15g daily, or 100g weekly.³
• Due to the degradation of corticosteroids by vitamin D3 analogues, concurrent application should be avoided.

Calcipotriol + Corticosteroid in Combination

• Stable commercial preparations of calcipotriol + betamethasone dipropionate have the dual benefit of controlling scalp psoriasis symptoms with a low risk of skin atrophy and without tachyphylaxis.^1,4
• Randomized, double-blind, controlled studies showed that the two agents in combination have a more rapid onset of action and greater efficacy than monotherapy with either agent.^5,6
• A two-compound formulation of betamethasone dipropionate 0.5mg/g + calcipotriol 50µg/g in a novel gel vehicle received Health Canada approval in November 2008 for the treatment of scalp psoriasis.
  • This new gel formulation achieved marked improvement to clearance in 92% of scalp psoriasis patients following once-daily use for up to 8 weeks.7
  • The gel vehicle improves cosmetic acceptability, minimizes irritation, facilitates ease of use, is odourless, and offers once-daily dosing.
  • Investigations reporting benefits of the new formulation did not use pretreatment or concomitant therapy with a descaling agent.^4,5,6,7
  • Optimal effects may be achieved if the agent remains on the scalp overnight or during the day.
  • After the treatment period, the agent should be removed by applying any mild, unmedicated shampoo to dry hair. Gently rub the shampoo into hair (in the treated area) to emulsify the gel medication, then wet hair, lather, and rinse.
  • Recently published findings support the new agent’s safety, tolerability, and efficacy when used once-daily, as needed, for up to 52 weeks.⁴
  • Studies report very similar rates of side-effects for all treatment groups, including placebo; the most common adverse event was pruritus.³
  • To avoid the potential effects on calcium metabolism, limit use to 15g daily, or 100g weekly.³

   

• Safety for use in pregnant and nursing women, as well as in patients aged =18 years, has not been established. It is not recommended for these patient populations.

Counseling of Patients with Scalp Psoriasis

• Patients consider scalp psoriasis to be the most difficult aspect of their disease, which can lead to loss of self-esteem, social stigmatization, and even depression.
  • A study showed that 1 in 3 patients are self-conscious of their scalp psoriasis, and 1 in 5 report depressive symptoms.⁸
  • As part of routine clinic assessments, evaluate psychosocial aspects and quality of life.
• Scratching and picking at scales can aggravate lesions and lead to spreading of the psoriatic plaques over a larger surface area (Koebner phenomenon).
• Reinforce management strategies during clinic visits (e.g., proper medication use, side-effects, antipruritic measures, cleansing, and grooming techniques).
  • Practitioners can explain to patients that the major goals of treatment are to relieve the itching and reduce the scaling. Antihistamines are not effective in controlling the itch.
  • Wearing light-coloured clothing can minimize the visibility of flakes.
• Patients can use OTC shampoos containing salicylic acid or tar to help soften and release the scales.
  • Inform patients of the potential for tar shampoos to stain light-coloured hair.
• Suggest patient participation in national organizations or web-based social networks. Psoriasis virtual communities can provide education, as well as psychological and social support.

Tips for Improving Treatment Adherence

• Nonadherence to treatment occurs in up to 40% of patients with psoriasis.⁹ Fears about treatment side-effects, the nuisance of using prescribed therapies, and dissatisfaction with the clinic consultation can discourage adherence.
• Devote time to patient education. When patients are given accurate information about their psoriasis and the selected treatment, their understanding of the therapeutic objectives and the negative impacts of nonadherence improves.
• Clinical strategies that can promote adherence include individualizing the treatment approach, encouraging patient input when making therapeutic decisions, choosing fast-acting topical agents, selecting treatments that facilitate ease of use (i.e., simple and convenient dosing), and regular monitoring of progress while undergoing therapy.

Conclusion

With the potential for escalating morbidity, diminished quality of life, and significant financial burden, it is essential for physicians to establish an ongoing rapport with psoriasis patients in order to successfully manage both the physical and emotional aspects of this chronic disease. Continuing efforts aimed at addressing unmet therapeutic needs have led to the development of new topical antipsoriatic therapies that are safer and more effective. The advent of two-compound agents that can target multiple pathogenic factors are proving to be particularly useful. The investigation of novel treatment combinations and new compounds for scalp psoriasis are ongoing in the quest to provide further enhancements in efficacy that will lead to improved patient adherence and treatment outcomes.

References

1. Papp K, et al. Scalp psoriasis: a review of current topical treatment options. J Eur Acad Dermatol Venereol 21(9):1151-60 (2007 Oct).
2. Zaghloul SS, et al. Objective assessment of compliance with psoriasis treatment. Arch Dermatol 140(4):408-14 (2004 Apr).
3. Xamiol® [calcipotriol and betamethasone dipropionate] product monograph. Thornhill, ON: LEO Pharma Inc. (2008 Nov).
4. Luger TA, et al. A study of the safety and efficacy of calcipotriol and betamethasone dipropionate scalp formulation in the long-term management of scalp psoriasis. Dermatology 217(4):321-8 (2008).
5. Jemec GB, et al. A new scalp formulation of calcipotriene plus betamethasone compared with its active ingredients and the vehicle in the treatment of scalp psoriasis: a randomized, double-blind, controlled trial. J Am Acad Dermatol 59(3):455-63 (2008 Sep).
6. van de Kerkhof PC, et al. A new scalp formulation of calcipotriol plus betamethasone dipropionate compared with each of its active ingredients in the same vehicle for the treatment of scalp psoriasis: a randomized, double-blind, controlled trial. Br J Dermatol 160(1):170-6 (2009 Jan).
7. Buckley C, et al. Calcipotriol plus betamethasone dipropionate scalp formulation is effective and well tolerated in the treatment of scalp psoriasis: a phase II study. Dermatology 217(2):107-13 (2008).
8. Chen SC, et al. Scalpdex: a quality-of-life instrument for scalp dermatitis. Arch Dermatol 138(6):803-7 (2002 Jun).
9. Richards HL, et al. Adherence to treatment in patients with psoriasis. J Eur Acad Dermatol Venereol 20(4):370-9 (2006 Apr).