Based on an article titled “Serum Levels of 25-Hydroxyvitamin D in Patients with Seborrheic Dermatitis: A Case-Control Study”
Originally written by: Rahimi et al., 2021
By: Murielle Nsiela
Seborrheic dermatitis is a common skin condition that mainly affects the scalp. However, it can affect other oily parts of the body as well, for example, the eyebrows, sides of the nose, face, ears, groin, chest, and eyelids. In addition, the skin condition can cause scaly patches, dandruff, and redness of the scalp.1
There are other names by which this disease is known, such as seborrheic eczema, dandruff, or seborrheic psoriasis. For babies, the condition is called cradle cap, leading to crusty and scaly patches on the scalp.1
The root cause of the disease is not well known. However, it has been suggested that it could be due to a fungus known as Malassezia found in oil secretion from the skin. Another related cause of seborrheic dermatitis is an improper response of the immune system.1 In addition, several factors can increase the likelihood of developing seborrheic dermatitis. These include:
- Parkinson’s disease and depression
- Neurological conditions, such as epilepsy
- Recipient of an organ transplant
- Hepatitis C
- Down syndrome
- Zinc deficiency
- Psoralen and ultraviolet-A therapy
Age and Gender:
Age and gender can potentially affect the susceptibility of developing seborrheic dermatitis. The condition is more common in people assigned male at birth than female and is more common in infants three months and younger or individuals aged between 30 to 60 years.
Lifestyle risk factors2:
There are lifestyle risk factors associated with developing seborrhoeic dermatitis, such as:
- Sleep deprivation
- Emotional stress
- Hair washing frequency
- Living in a climate that is cold and dry
The link to hair loss:
Furthermore, there have been suggestions on whether seborrheic dermatitis causes hair loss. According to Very Well health, there is an association between hair loss and the condition - when oil production increases, it can cause irritation and inflammation that will eventually lead to itching. Intense itching of the scalp can affect the hair follicles, which obstructs hair growth and leads to hair loss.3
However, hair loss from this condition is rare and often reversible and usually occurs when there is a growth of Malassezia fungus. The overproduction of the fungus, just like oil, causes inflammation which further affects hair follicles and leads to hair loss.3
A total of 289 patients participated, and the study was conducted in the same season for all participants in autumn 2019. This was to avoid differences in vitamin D levels, which could have affected the results. Among the patients, 60 had facial seborrheic dermatitis, 52 had scalp seborrheic dermatitis, and six had both.
Furthermore, the study looked into the vitamin D status in both the healthy and the case study groups. The results from the study showed that vitamin D levels were lower in the case group with facial and/or scalp dermatitis (20.71) compared to the control group (23.91). In addition, they looked into whether individuals had sufficient, insufficient and deficient amounts of vitamin D.4
In individuals who only had facial seborrheic dermatitis, 8 had sufficient, 20 had insufficient, and 34 were deficient in vitamin D. In individuals with scalp seborrheic dermatitis, 16 had sufficient levels, 22 had insufficient, and 18 were deficient. The frequency of the vitamin D status in the healthy group showed that 39 had sufficient, 79 had insufficient, and 53 were deficient. Overall, the results showed that vitamin D insufficiency was more common amongst the healthy group. However, vitamin D deficiency was more common in individuals with seborrheic dermatitis on both the face and scalp.4
In conclusion, the data showed that serum vitamin D was lower in individuals with seborrheic dermatitis. In addition, individuals who had facial seborrheic dermatitis had significantly lower vitamin D levels than those who had the condition on the scalp; furthermore, the more severe the condition, the lower the vitamin D levels. However, it was suggested that further studies with a larger population and with individuals from different geographical backgrounds would be required to make the data found more reliable on the effects of vitamin D on seborrheic dermatitis.
- Seborrheic dermatitis - Symptoms and causes [Internet]. Mayo Clinic. 2022 [cited 10 April 2022]. Available from: https://www.mayoclinic.org/diseases-conditions/seborrheic-dermatitis/symptoms-causes/syc-20352710
- Multiple Factors Are Likely at Play When It Comes to This Skin Disease [Internet]. Verywell Health. 2022 [cited 10 April 2022]. Available from: https://www.verywellhealth.com/seborrheic-dermatitis-causes-4769875
- The Link Between Seborrheic Dermatitis and Hair Loss [Internet]. Verywell Health. 2022 [cited 10 April 2022]. Available from: https://www.verywellhealth.com/seborrheic-dermatitis-hair-loss-5185124
- Rahimi et al., 2021 - Rahimi S, Nemati N, Shafaei-Tonekaboni S. Serum Levels of 25-Hydroxyvitamin D in Patients with Seborrheic Dermatitis: A Case-Control Study. Dermatology Research and Practice. 2021;2021:1-5.
- Saunte D, Gaitanis G, Hay R. Malassezia-Associated Skin Diseases, the Use of Diagnostics and Treatment. Frontiers in Cellular and Infection Microbiology. 2020;10.
- How the Growth Cycle of Hair Follicles Works [Internet]. Verywell Health. 2022 [cited 10 April 2022]. Available from: https://www.verywellhealth.com/hair-follicle-1068786
- Office of Dietary Supplements - Vitamin D [Internet]. Ods.od.nih.gov. 2022 [cited 10 April 2022]. Available from: https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/