He was a bright 18-year-old young man with a golden blond head of hair, dressed to the T. I had just graduated from my second fellowship in 2002 and had no clue what to do with him. The young man presented with weight gain, elevated sugar levels, and stretch marks. He clearly had Cushing’s disease, but all the MRI and blood tests I and others ordered, did not reveal why he had Cushing. Cushing’s Disease is a condition where the body produces excessive and uncontrolled levels of cortisol (a natural form of prednisone). I referred him to endocrinologists all around New York, but they, too, had no clue. Some said it’s his diet and likely just a growth spurt, not Cushing.
Besides Cushing, he also came for his scalp psoriasis. He was prescribed steroid scalp foam which he has been using for about 3 years religiously. Although his psoriasis had cleared, he felt he had to use the steroid foam to prevent its recurrence. The foam was refilled by his doctors, and he was happy with his scalp being clear. Finally, a pediatric endocrinologist resolved the mystery- his Cushing was from his topical steroid foam application on the small surface area of his scalp. I was shocked, as were my professors. The foam was stopped, and he slowly returned back to normal.
Topical steroids work by reducing inflammation (often presenting as itching with or without a rash) and suppressing the immune system in the area where they are applied. While topical steroids are applied directly to the affected area and generally have minimal systemic absorption, meaning they are not likely to affect blood sugar levels, they can be absorbed into the bloodstream and circulate throughout the body. This, in turn, can affect glucose metabolism and has been reported, in rare cases, to increase blood sugar levels.
The likelihood of a topical steroid causing a temporary rise in blood sugar levels is increased with the use of a high potency topical steroid that is applied for a long time, usually years, but could happen even after 2 weeks of use, when it is applied on a large surface area where the skin barrier is broken and the absorption level is thus increased. The potency of topical steroids is ranked from strongest (Class 1, such as Clobetasol ointment) to weakest (Class 7, such as hydrocortisone 2.5 ointments) based on their ability to cause local vasoconstriction (blood vessel narrowing). Ointments, due to their occlusive nature, are in general more potent than other formulations (with some variations based on the body area and disease condition).
What has the literature reported:
A study published in the Journal of the American Academy of Dermatology in 2012 found that the risk of hypothalamic-pituitary-adrenal (HPA) axis suppression was highest with the use of high-potency topical steroids, especially when applied to large areas of the body or when used under occlusion (covering the area with a bandage or dressing).
Another study published in 2017 in the Journal of Cutaneous Medicine and Surgery found that long-term use of topical steroids was associated with an increased risk of HPA axis suppression, even with low-potency medications.
What is the mechanism by which a topical steroid can elevate our sugar levels:
Topical steroids, if absorbed in the bloodstream, can have an effect on the HPA axis, which is a system that helps regulate stress responses and hormone levels in the body. This in turn suppresses the adrenal glands responsible, among other things, for cortisol production. When topical steroids are applied to the skin, they can be absorbed into the bloodstream and suppress the activity of the HPA axis by increasing prednisone levels. Both Cortisol (a natural steroid) and prednisone (a synthetic steroid) affect our body in the same way (they have small differences where cortisol is less potent and has a shorter duration of action than prednisone). As the body senses elevated internal steroid levels it suppresses its natural steroid production, such as cortisol, which can have many negative effects on health. In relation to glucose production, cortisol is a hormone that helps regulate blood sugar levels, and when the HPA axis is not in control of the cortisol or prednisone levels, the levels can rise too high. High blood prednisone/cortisol levels can lead to insulin resistance and high blood sugar. Exogenous prednisone can cause a Cushing like steroid induced reaction with weight gain, stretch marks, and diabetes or locally (I've seen that more often) it can lead to steroid induced rosacea.
As dermatologists, we often use high doses of oral prednisone for short periods of time as 2 to 3 weeks to treat poisen ivy or for longer periods to treat autoimmune disorders, without any long term sequlae. Still, one should not use topical steroids indiscrimanatly. All steroid creams, including the over the counter low potency topical steroids, should be used in moderation and under the supervision of an experienced physician. The key is to use the topical steroids according to the instructions of your healthcare care provider, avoid occlusion or skin folds, avoid prolonged use on large body surface areas, and have the skin evaluated frequently by a board certified dermatologist for any signs of steroid atrophy (skin thinning with the appearance of blood vessels and occasional pimples). In the worst case scenario, even if you have experienced HPA axis suppression, If the steroid is stopped in time, in the majority of cases, the cushing’s disease or steroid atrophy can be reversed.
As we say at Levit Dermatology: health and beauty is our duty, but we can not do it without your help. Or as Jerry Maguire wisely said, “Help me help you”. Wishing you all health and beauty. Be good, do good, and may good come your way.