Antiandrogens
Seborrhoea, which is sometimes associated with seborrhoeic dermatitis, is recognized as an androgen-sensitive condition – that is, it is caused or aggravated by androgen sex hormones such as testosterone and dihydrotestosterone – and is a common symptom of hyperandrogenism (e.g., that seen in polycystic ovary syndrome). In addition, seborrhoea, as well as acne, are commonly associated with puberty due to the steep increase of androgen levels at that time.In accordance with the involvement of androgens in seborrhoea, antiandrogens, such as cyproterone acetate, spironolactone, flutamide, and nilutamide, are highly effective in alleviating the condition. As such, they are used in the treatment of seborrhoea, particularly severe cases. While beneficial in seborrhoea, effectiveness may vary with different antiandrogens; for instance, spironolactone (which is regarded as a relatively weak antiandrogen) has been found to produce a 50% improvement after three months of treatment, whereas flutamide has been found to result in an 80% improvement within three months. Cyproterone acetate, similarly more potent and effective than spironolactone, results in considerable improvement or disappearance of acne and seborrhoea in 90% of patients within three months.Systemic antiandrogen therapy is generally used to treat seborrhoea only in women, not in men, as these medications can result in feminization (e.g., gynecomastia), sexual dysfunction, and infertility in males. In addition, antiandrogens theoretically have the potential to feminize male fetuses in pregnant women and, for this reason, are usually combined with effective birth control in sexually active women who can or may become pregnant. Antihistamines
Antihistamines are used primarily to reduce itching, if present.
In children and babies, excessive vitamin A intake or issues with Δ6-desaturase enzymes have been correlated with increased risk. Seborrhoeic dermatitis-like eruptions are also associated with vitamin B6 deficiency. Those with immunodeficiency (especially infection with HIV) and with neurological disorders such as Parkinsons disease (for which the condition is an autonomic sign) and stroke are particularly prone to it. Climate
Low humidity and low temperature are responsible for high frequency of seborrheic dermatitis. Fungi
The condition is thought to be due to a local inflammatory response to over-colonization by Malassezia fungi species in sebum-producing skin areas including the scalp, face, chest, back, underarms, and groin. This is based on observations of high counts of Malassezia species in skin affected by seborrhoeic dermatitis and on the effectiveness of antifungals in treating the condition. Such species of Malassezia include M. furfur (formerly Pityrosporum ovale), M. globosa, M. restricta, M. sympodialis, and M. slooffiae. Although Malassezia appears to be the central predisposing factor in seborrhoeic dermatitis, it is thought that other factors are necessary for the presence of Malassezia to result in the pathology characteristic of the condition. This is based on the fact that summer growth of Malassezia in the skin alone does not result in seborrhoeic dermatitis. Besides antifungals, the effectiveness of anti-inflammatory drugs, which reduce inflammation, and antiandrogens, which reduce sebum production, provide further insights into the pathophysiology of seborrhoeic dermatitis. Eunuchs, owing to their low androgen levels and small sebaceous glands, do not develop seborrheic dermatitis.