Although SD can affect people of any age, according to the NEA it’s most common in infants and adults between the ages of 30 and 60. “Among adults and teens, the condition is more common in males.”

The exact cause of SD is still unknown, however several factors, including hormones, have been implicated. According to Tucker et al. the onset of SD appears to be linked to the interplay of normal microscopic skin flora (especially Malassezia spp.), the composition of lipids on the skin surface, and individual susceptibility. “The Malassezia overgrows, and the immune system seems to overreact to it, leading to an inflammatory response that results in skin changes,” explained the NEA. 

Common triggers for seborrheic dermatitis include: 

• Stress 
• Hormonal changes or illness 
• Harsh detergents, solvents, chemicals, and soaps 
• Using alcohol-based lotions 
• Cold, dry weather 
• Some medications, including psoralen, interferon, and lithium 
• Other skin disorders, including rosacea, psoriasis, and acne

SYMPTOMS 

While symptoms can occur a bit differently in each person according to Cedars-Sinai, they can include skin that is bumpy, covered with flakes (dandruff on the scalp, eyebrows, facial hair), covered with yellow scales or crusts, cracked, greasy, itchy, leaking fluid, painful, red, or orange.

TREATMENT 

SD is a long-term condition that cannot be cured. However, there are many effective treatments available to manage symptoms. “The goal of treatment should be to provide safe and effective treatment that improves symptoms, reduces recurrence, and causes minimal side effects,” said Piquero-Casals et al. in Topical Non-Pharmacological Treatment for Facial Seborrheic Dermatitis (published in Dermatol Ther (Heidelb). 2019;9(3):469-477). “As the nature of the condition is chronic, treatment should aim to control the frequency and severity of flare-ups.” 

Treatment is based on where the SD presents on the patient’s body as well as severity. In general, Johnson et al. advised that hygiene issues play a key role in controlling SD. “Frequent cleansing with soap removes oils from affected areas and improves seborrhoea. Patients should be counselled that good hygiene must be a lifelong commitment. Outdoor recreation, especially during summer, will also improve seborrhoea, although caution should be taken to avoid sun damage,” (Treatment of Seborrheic Dermatitis published in Am Fam Physician. 2000 May 1;61(9):2703-2710).

“Various pharmacological treatments are available, including antifungal agents, keratolytics, topical low-potency steroids, and calcineurin inhibitors,” Piquero-Casals et al. explained. “All of them provide several benefits, but they also have potential side effects. SD tends to have a chronic, recurrent course. To avoid the long-term use of drugs, topical non-pharmacological products such as cosmetics or medical devices may improve clinical outcomes. Products with antimicrobial and anti-inflammatory ingredients such as zinc, piroctone olamine, dihydroavenanthramide, biosaccharide gum-2, and stearyl glycyrrhetinate may speed facial seborrheic dermatitis (FSD) recovery, and avoid flare-ups. Finally, the use of specific cleansers, moisturisers, and sunscreens formulated as light creams or gel/creams should be strongly recommended to all FSD patients,” the authors concluded. 

REFERENCES:  

• https://nationaleczema.org/eczema/types-of-eczema/seborrheic-dermatitis/ 
• https://my.clevelandclinic.org/health/diseases/14403-seborrheic-dermatitis 
• Tucker D, Masood S. Seborrheic Dermatitis. [Updated 2021 Aug 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK551707/ 
• https://my.clevelandclinic.org/health/diseases/14403-seborrheic-dermatitis 
• https://www.cedars-sinai.org/health-library/diseases-and-conditions/s/seborrheic-dermatitis.html 
• Piquero-Casals J, Hexsel D, Mir-Bonafé JF, Rozas-Muñoz E. Topical Non-Pharmacological Treatment for Facial Seborrheic Dermatitis. Dermatol Ther (Heidelb). 2019;9(3):469-477. doi:10.1007/s13555-019-00319-0 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6704200/ 
• Johnson BA, Nunley JR. Treatment of seborrheic dermatitis. Am Fam Physician. 2000 May 1;61(9):2703-10, 2713-4. PMID: 10821151. https://www.aafp.org/afp/2000/0501/p2703.html