By Batya Swift Yasgur, MA, LSW

“Cortisol” has become a household word, popularized by social media and tagged in videos that garnered nearly 800 million views last year. This is linked to the also trending term “moon face,” which TikTok influencers and others have suggested is caused by high cortisol levels and, conversely, can be reduced through stress reduction.

Although it’s true that cortisol is a hormone associated with stress, elevated stress levels are unlikely, by themselves, to cause the rounded facial features associated with “moon face.”

“When we hear the term ‘moon face,’ we’re typically referring to Cushing syndrome [CS] or treatment with prolonged high-dose glucocorticoids,” Anat Ben-Shlomo, MD, co-director of the Multidisciplinary Adrenal Program, Pituitary Center, Division of Endocrinology, Diabetes and Metabolism at Cedars-Sinai Medical Center, Los Angeles, told Medscape Medical News. Medscape Medical News previously discussed moon face in an article detailing how to diagnose CS.

Ben-Shlomo noted that the labels “moon face” and “moon facies” should be avoided for their potentially derogatory, unprofessional-sounding connotations, and that the preferred terms are “rounded face” or “round plethoric face.”

There are several disorders that can be associated with facial roundness, not all of which relate to elevated cortisol.

“It’s important for clinicians to be able distinguish between presentations due to other pathophysiologies, identify the unique constellation of Cushing-associated signs and symptoms, engage in a differential diagnosis, and treat whatever the condition is appropriately,” Katherine Sherif, MD, professor and vice chair of academic affairs, Department of Medicine, Thomas Jefferson University, Philadelphia, told Medscape Medical News.

The Unique Presentation of CS

CS results from “prolonged elevation” in plasma cortisol levels due to either exogenous steroid use or excess endogenous steroid production.

“The shape of the face isn’t the only feature associated with CS,” Ben-Shlomo said. “There’s central obesity, particularly in the neck, supraclavicular area, chest, and abdomen. You sometimes see a posterior cervical thoracic fat pad, colloquially — but unprofessionally — called a ‘cervical hump.’ Simultaneously, the arms and legs are getting thinner.” The development of a round, plethoric face is common in long-standing significant CS, and a reddening of the skin can appear.

Additional symptoms include hirsutism and acne. “These can also be seen in other conditions, such as PCOS [polycystic ovary syndrome] but, combined with the other facial features, are more suggestive of CS,” Ben-Shlomo said.

Deep, wide purple striae appear in the trunk, breast, upper arms, and thighs, but not in the face, Ben-Shlomo advised. These appear as the fragile, thinning under-skin breaks when the patient gains weight.

Additional metabolic issues that can occur comorbidly include insulin resistance and diabetes, hypertension, osteoporosis, dyslipidemia, ecchymoses, increased susceptibility to infections, mood changes, cognitive dysfunction, low libido, infertility, weakness of muscles in the shoulders and thighs, episodes of bleeding and/or clotting, and an increased risk for heart attacks and strokes, Ben-Shlomo said.

“Not everyone presents with full-blown disease, but if you see any of these symptoms, be suspicious of CS and conduct a biochemical evaluation.” Three screening tests to use as a starting point are recommended by the Pituitary Society’s updated Consensus on Diagnosis and Management of Cushing’s Disease. The tests should be repeated to account for intra-patient variability. If two or all three tests are positive, clinicians should be suspicious of CS and move to additional testing to identify the underlying cause, Ben-Shlomo said.

‘Subclinical’ CS

Ben-Shlomo highlighted a condition called minimal autonomous cortisol secretion (formerly “subclinical CS”). “This condition is found when a person has an adrenal nodule that produces cortisol in excess, however not to levels observed in CS. An abnormal finding on the overnight 1-mg low-dose dexamethasone suppression test (LDDST) will identify this disorder, showing mildly unsuppressed morning cortisol level, while all other tests will be within normal range.”

She described minimal autonomous cortisol secretion as a form of “smoldering CS,” which has become more commonly diagnosed. “The condition needs to be treated because the patient can develop insulin resistance, metabolic syndrome, and osteoporosis over time.”

Once a cause has been determined, the optimal course of action is to take a multidisciplinary approach because CS affects multiple systems.

‘Pseudo-Cushing Syndrome’

A variety of abnormalities of the hypothalamus-pituitary adrenal (HPA) axis can be associated with hypercortisolemia and a rounder facial appearance but aren’t actually CS, Ben-Shlomo said.

Often called “pseudo-Cushing syndrome,” these conditions have recently been renamed “non-neoplastic hypercortisolism” or “physiologic non-neoplastic endogenous hypercortisolism.” They share some clinical and biochemical features of CS, but the hypercortisolemia is usually secondary to other factors. They increase the secretion of hypothalamic corticotropin-releasing hormone, which stimulates adrenocorticotropic hormone (ACTH) and adrenal cortisol secretion.