Can a patient have Cushing's disease without the presence of striae?

Can a Patient Have Cushing's Disease Without Striae?

Yes, patients can absolutely have Cushing's disease without striae—striae are present in only approximately 53% of pediatric cases and are not required for diagnosis. 1

Clinical Reality of Striae in Cushing's Disease

The absence of striae does not exclude Cushing's disease, and this is particularly important to understand when evaluating patients:

Age-Dependent Presentation

• Striae are more common in older patients: In a pediatric cohort, the mean age of patients WITH striae was 15.2 years, compared to only 10.3 years in those WITHOUT striae. 1
• This suggests striae develop with longer disease duration or may be related to pubertal skin changes combined with hypercortisolism. 1

Striae Are NOT Among the Most Specific Features

While wide purple/violaceous striae (>1 cm) are considered characteristic when present, the most specific clinical features for Cushing's syndrome are actually: 2, 3

• Abnormal fat distribution (supraclavicular and temporal fossae accumulation) 2, 3
• Proximal muscle weakness 2, 3
• Decreased linear growth with continued weight gain in children 3

Cardinal Features That Should Trigger Evaluation

Focus on these findings instead of waiting for striae to appear: 2

• Central obesity with supraclavicular fat accumulation 2
• Moon facies (facial plethora and rounding) 2
• Buffalo hump (dorsocervical fat pad) 2
• Facial plethora 2
• Proximal muscle weakness or wasting 2

In Pediatric Patients Specifically

Screen for Cushing's syndrome in children with obesity ONLY when weight gain is unexplained AND combined with either: 4

• Decrement in height standard deviation score (SDS), OR 4
• Decreased height velocity 4

This combination has high sensitivity and specificity for Cushing's syndrome in children and does not require striae to be present. 4

Rare Cases Without Classic Phenotype

A documented case exists of a patient with confirmed Cushing's disease who lacked the entire classical phenotype (including striae, central adiposity, hypertension, and bruising) due to a defect in 11β-hydroxysteroid dehydrogenase type 1 activity. 5 This demonstrates that biochemical hypercortisolism can exist without typical physical findings.

Diagnostic Approach When Striae Are Absent

Proceed with biochemical testing based on other clinical features: 6, 2

1. Initial screening with 2-3 tests: 6

   • 24-hour urinary free cortisol (UFC) 6
   • Late-night salivary cortisol 6
   • 1 mg overnight dexamethasone suppression test 6

2. Confirmation requires: 6

   • Morning cortisol >50 nmol/L (>1.8 μg/dL) after 1 mg dexamethasone 6
   • Loss of cortisol circadian rhythm 6

Clinical Pitfall to Avoid

Do not dismiss Cushing's disease simply because striae are absent. The American Heart Association notes that Cushing's disease is suggested by "abdominal striae, particularly if pigmented" but does not state this is required for diagnosis. 4 The emphasis on "particularly if pigmented" indicates that wide purple striae increase specificity, but their absence does not rule out disease. 4

In subclinical hypercortisolism, patients specifically do NOT exhibit the classic features including purple striae, easy bruising, or proximal muscle weakness, yet still have pathologic cortisol excess. 7