Hormone changes in acne
Patients with acne often have oily skin (seborrhoea). This may be because of:
- High overall levels of sex hormones (mainly the androgen, testosterone).
- Increased free testosterone because of low levels of circulating sex-hormone-binding-globulin (SHBG). Normally there is little free testosterone circulating in the blood as it is tightly bound by SHBG.
- More active conversion of weaker androgens to stronger androgens such as dihydroxytestosterone (DHT) by the enzyme 5-reductase within the skin.
- Higher sensitivity of the skin to DHT.
The general term used to describe excessive male hormone in females is hyperandrogenism.
What conditions cause high levels of androgens in women?
About 50% of females with acne have an imbalance of hormones although this is usually only mild.
It is seldom necessary to test hormone levels in patients with acne unless there are other features suggesting they are excessive (hyperandrogenism). Such features include balding (androgenetic alopecia), hirsutism, clitoral enlargement (virilisation).
High levels of male sex hormones may arise from:
- Disease of the ovaries
- Polycystic ovary syndrome: this results in hirsutism, infertility and/or irregular menstruation
- Benign (non-invasive) or malignant (cancerous) ovarian tumours
- Disease of the adrenal gland
- Partial deficiency of the adrenal enzyme 21-hydroxylase (late onset CYP21A2 defiency) and other forms of congenital adrenal hyperplasia
- Benign or malignant adrenal tumours
- Disease of the pituitary gland
- Cushing's syndrome due to excessive adrenocorticotrophic hormone (ACTH) causes moon face, truncal obesity, thin skin, easy bruising, stretch marks (striae), hirsutism and tiredness
- Acromegaly (gigantism) due to excessive growth hormone production
- Tumour producing prolactin which causes inappropriate milk secretion (galactorrhoea).
- Obesity and the metabolic syndrome – more androgens are made in body fat
Most patients with acne have normal circulating levels of androgenic hormones but the affected sebaceous glands have increased activity of 5-reductase.
What tests should be done?
If there are symptoms or signs to suggest hyperandrogenism, baseline tests may be useful to find out the cause.
- Blood tests for hormone levels: FSH (follicle stimulating hormone), LH (luteinising hormone), estrodiol, prolactin, testosterone, SHBG (sex hormone binding globulin), 17-0H progesterone, thyroid function.
- Pelvic ultrasound scan to evaluate ovarian cysts
Patients with acne and significant menstrual disturbance, severe hirsutism, suspected Cushing syndrome or acromegaly, total testosterone of >5nmol/L or other hormone abnormalities are best to consult an endocrinologist.
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