A study that investigated available evidence on seborrheic dermatitis offers a summary of recommended diagnosis and management strategies for the common chronic inflammatory skin disorder. The findings from the study were published in Clinical, Cosmetic and Investigational Dermatology.
Overview of Diagnostic Approaches
A review of the available literature published from January 2017 to April 2022 on seborrheic dermatitis yielded information on the following recommended diagnostic strategies for the disorder:
- Blood tests: Given that seborrheic dermatitis could be a marker for acquired immunodeficiency syndrome, blood tests may be necessary to identify underlying causes of the disorder. In addition, more severe cases of seborrheic dermatitis could be observed in association with inherited (acrodermatitis enteropathica) or acquired neonatal/adult forms of zinc deficiency, in addition to other nutritional deficiencies.
- Dermatoscopy: A noninvasive technique that can offer rapid and magnified skin observation as well as detection of morphologic features not seen by the human eye alone. Dermatoscopy could help differentiate scalp seborrheic dermatitis from other common scaling disorders (eg, psoriasis or tinea capitis) according to specific dermoscopy hallmarks.
- Histological examination: Spongiosis and psoriasiform hyperplasia are typically seen in the epidermis of acute seborrheic dermatitis cases. In chronic disease, there is often marked psoriasiform epidermal hyperplasia and parakeratosis, along with dilation of superficial dermal venules.
- Instrumental and/or laboratory evaluations: The investigators explained that sebutape/sebometry investigations, stratum corneum hydration/skin surface pH measurements, and microscopic/culture identifications “can provide useful information to define some epidemiological and etiopathogenetic” aspects of seborrheic dermatitis.
Overview of Recommended Treatments
According to the Evidence-Based Medicine (EBM) criteria, the investigators classified the available topical, systemic agents, and physical treatments for scalp and nonscalp SD from level A (strong evidence for efficacy) to level E (least evidence of efficacy).
Seborrheic Dermatitis of the Scalp in Adults: Topical Therapy
The investigators made evidence-based comments on the several available topical therapies for scalp seborrheic dermatitis in adults:
- Betamethasone valerate (Level A): Available in 0.12% foam; prolonged use is not recommended due to the possibility of side effects (eg, atrophy and telangiectasias).
- Ciclopirox (Level A): Available as a 1% to 1.5% shampoo and 0.77% gel, with no statistically significant difference in clinical response for higher vs lower concentrations.
- Clobetasol propionate (Level A): A 0.05% shampoo can be used alone or with antifungal agents; avoid prolonged use to prevent side effects.
- Ketoconazole (Level A): Once weekly topical ketoconazole 2% shampoo for 6 months may be effective for preventing relapse; twice daily continuative use of 2% foam for up to 12 months features a high safety profile; 2% gel has rapid efficacy and low rate of recurrences following discontinuation; 2% foaming gel results in significant reduction of erythema and Pityrosporum orbiculare count.
- Miconazole (Level A): A 2% solution plus 1% hydrocortisone solution may be more effective than 2% miconazole alone.·
- Propylene glycol (Level A): A 15% solution leads to significant reduction of P. orbiculare count by microbiological evaluation.
Seborrheic Dermatitis of the Non-Scalp Area in Adults: Topical Therapy
- Ciclopirox (Level A): Available in 1% cream; limited data support efficacy of compared with other topical antifungals.
- Clotrimazole (Level A): Available in 1% cream; limited data support short-term efficacy compared with corticosteroids.
- Desonide (Level A): Available in 0.05% cream; similar efficacy compared with nonsteroidal AIAF product.
- Hydrocortisone (Level A): Available in 1% cream; limited data to support efficacy.
- Ketoconazole (Level A): 1% to 2% cream/foam/gel; results in significant reduction of Malassezia with 2% cream.
- Lithium succinate/gluconate (Level A): 8% ointment; limited data to support efficacy vs ketoconazole 2% cream.
- Pimecrolimus/tacrolimus (Level A): 1% cream and 0.03% to 0.1% ointment; improved side effect profile compared with topical corticosteroids.
Systemic Therapy in Adults
The lipophilic molecule terbinafine (Level A) has demonstrated superior efficacy over moisturizing ointment and placebo, with a safe pharmacological profile in the systemic treatment of seborrheic dermatitis, according to the investigators. The researchers added that itraconazole (Level B), a highly keratinophilic and lipophilic triazole agent, features an anti-inflammatory effect which could play a potential role in managing seborrheic dermatitis.
According to the researchers, patients with seborrheic dermatitis often experience improvements in their condition during the summer months. The researchers referenced studies which show that ultraviolet (UV) A and UVB light exposure may have anti-inflammatory and/or inhibiting effects on Malassezia yeasts, potentially supporting the rationale of using UV therapy to treat seborrheic dermatitis. However, the investigators noted that “limited clinical evidence supports the advantages of UVB phototherapy (Level C) in diffuse and resistant” forms of the skin disorder.
The researchers wrote that patients with seborrheic dermatitis should be advised that their disorder “is a chronic disease and therefore a complete resolution after topical or systemic therapy is a difficult goal to achieve.” As such, maintenance therapy will often be necessary.
Patients with seborrheic dermatitis should also be educated on how various environmental factors (temperature and humidity as well as excessive sun exposure), physical/psychological stress, unhealthy lifestyle, and cosmetic use may contribute to or worsen their disorder, the investigators concluded. “On this last regard,” they wrote, “it is important not to let patients freely choose the cosmetic product they prefer, because of the high risk of compromising treatment outcome.”
Dall’Oglio F, Nasca MR, Gerbino C, Micali G. An overview of the diagnosis and management of seborrheic dermatitis. Clin Cosmet Investig Dermatol. 2022;15:1537-1548. doi:10.2147/CCID.S284671