A 69-year-old man is referred for treatment of actinic keratoses on his arms and scalp. While examining the patient, a facial rash was observed. On questioning the patient stated that the condition had been present for several years. The rash waxes and wanes in intensity but remains asymptomatic. The patient’s medical history includes hypertension and arthritis. Physical examination reveals well-demarcated erythema with fine scales of the nasolabial folds, mustache, and external ear canal.
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Presenting with a papulosquamous morphology, seborrheic dermatitis (SD) is a common inflammatory skin disease.1 Multiple factors have been linked to its pathogenesis. A few proposed mechanisms include alteration of the skin’s microbiota,2 increased phospholipase activity induced by Malassezia colonization,3 and disruption of the epidermal barrier.4 The incidence of SD is increased in patients with AIDS, Alzheimer disease, and Parkinson disease.
The occurrence of SD is bimodal, peaking in infancy and in middle-aged to elderly populations. The condition is typically characterized by greasy scales, sometimes paired with erythema and itchiness. Adult SD manifests on the face, scalp, and chest. A common finding in SD is a symmetrical pattern involving the central third of the face including the nasolabial and alar folds.5 Infantile SD (ISD) may affect the scalp and face as well as the diaper region, skin creases of the neck, and axilla. Itching is uncommon in infants.6
Management of SD should take into consideration the patient’s age, distribution of the rash, and severity of the condition. For ISD, treatment of the scalp often includes a softening agent followed by mechanical removal of scales along with topical antifungals and low-potency corticosteroids.6 Evidence-based Danish guidelines for adult SD support antifungal azoles as first-line treatment adding short courses of topical corticosteroids or topical calcineurin inhibitors for enhanced anti-inflammatory effect.7
Sidney Lampert is a medical student at the Drexel University College of Medicine, in Philadelphia. Stephen Schleicher, MD, is director of the DermDox Dermatology Centers, associate professor of medicine at Geisinger Commonwealth Medical College, and clinical instructor of dermatology at Arcadia University and Kings College.
- Sanders MGH, Pardo LM, Franco OH, Ginger RS, Nijsten T. Prevalence and determinants of seborrhoeic dermatitis in a middle-aged and elderly population: the Rotterdam Study. Br J Dermatol. 2018;178(1):148-153. doi:10.1111/bjd.15908
- Tao R, Li R, Wang R. Skin microbiome alterations in seborrheic dermatitis and dandruff: a systematic review. Exp Dermatol. 2021;30(10):1546-1553. doi: 10.1111/exd.14450
- Honnavar P, Chakrabarti A, Prasad GS, Singh P, Dogra S, Rudramurthy SM. β-Endorphin enhances the phospholipase activity of the dandruff causing fungi Malassezia globosa and Malassezia restricta. Med Mycol. 2017;55(2):150-154. doi:10.1093/mmy/myw058
- Turner GA, Hoptroff M, Harding CR. Stratum corneum dysfunction in dandruff. Int J Cosmet Sci. 2012;34(4):298-306. doi:10.1111/j.1468-2494.2012.00723.x
- Tucker D, Masood S. Seborrheic dermatitis. In: StatPearls [Internet]. StatPearls Publishing; 2023. Updated February 16, 2023. Accessed September 6, 2023.
- Victoire A, Magin P, Coughlan J, van Driel ML. Interventions for infantile seborrhoeic dermatitis (including cradle cap). Cochrane Database Syst Rev. 2019;3(3):CD011380. doi:10.1002/14651858.CD011380.pub2
- Hald M, Arendrup MC, Svejgaard EL, et al. Evidence-based Danish guidelines for the treatment of Malassezia-related skin diseases. Acta Derm Venereol. 2015;95(1):12-19. doi:10.2340/00015555-1825