Although IGF-1 and androgen levels cause acne in acne prone individuals, the levels are roughly the same for people with and without acne.
Mark Cappel, MD; David Mauger, PhD; Diane Thiboutot, MD, Correlation Between Serum Levels of Insulin-like Growth Factor 1, Dehydroepiandrosterone Sulfate, and DihydroTestosterone and Acne Lesion Counts in Adult Women -ARCH DERMATOL/VOL 141, MAR 2005
Hormonal changes - common during adolescence, pregnancy, or menstruation (acne tends to flare up 2 - 7 days before menstruation begins)
Family history of acne
Using oily cosmetic or hair products
Certain medications. E.g. corticosteroids, androgens, oral contraceptives, lithium, halogens, isoniazid, phenytoin, phenobarbital, and high levels of iodine (such as from kelp)
Sweating / friction. Caused by headbands, back packs, bicycle helmets, or tight collars
Squeezing / picking comedones
Thyroid Hormones increase sebum production
Acne and its Therapy by Guy F. Webster and Anthony V. Rawlings
• Thyroidectomy in rats decreases the rate of sebum secretion - andadministration of thyroxine reverses thiseffect
Thody AJ, Shuster S. A study of the relationship between the thyroid gland and sebum secretion in the rat. J. Endocrinol 1972; 54:239-244.
• Thyroxine given to hypothyroid patients increased sebum secretion rate
Goolamali SK, Evered D, Shuster S. Thyroid disease and sebaceous function. Br Med J 1973; 1:432-433
• Thyroid hormone nuclear receptors havebeen demonstrated in human scalp follicles - in the nuclei of the outer root sheath cells,dermal papilla cells, sheath cells, and sebaceous gland cells
Ahsan MK, Urano Y, Kato S, Oura H, Arase S. Immunohistochemical localisation of thyroid hormone nuclear receptors in human hair follicles and in vitro effect of L-triiodothyronine on cultured cells of hair follicles and skin. Lab Med Invest 1998:44:179-184.
INSULIN, thyroid-stimulating hormone (TSH), and hydrocortisone stimulate sebocyte proliferation
Zouboulis CC, Xia L, Akamatsu H, Seltmann H, Fritsch M, Hornemann S, Ruhl R, Chen W, Nau H, Orfanos CE1998 The human sebocyte culture model provides new insights into development and management of seborrhoea and acne. Dermatology196:21-31 PubMed
