Initial/Screening: Clinical diagnosis based on characteristic morphology, central facial distribution, and episodic flushing triggered by specific factors.
Confirmatory/Gold Standard: Clinical evaluation. Diagnostic testing generally unnecessary.
Key Labs: None indicated routinely. Antinuclear antibody (ANA) only if ruling out systemic lupus erythematosus (SLE).
Imaging: Not indicated.
Biopsy: Rarely indicated; reserved for atypical presentations to exclude cutaneous lupus, granulomatous disease (sarcoidosis), or demodicosis.
Differential Diagnostics
Acne Vulgaris:
Diff by presence of comedones (open/closed); involves extrafacial sites (back, chest, shoulders); typically younger age of onset (adolescence).
Systemic Lupus Erythematosus (Malar Rash):
Diff by sparing of nasolabial folds, absence of pustules/papules, systemic features (fever, arthritis, serositis, nephritis), and (+) ANA/anti-dsDNA.
Seborrheic Dermatitis:
Diff by greasy, yellowish scale predominantly over nasolabial folds, eyebrows, and scalp; absence of flushing or pustules.
Perioral Dermatitis:
Diff by papules/pustules confined to the perioral area with a distinct rim of sparing around the vermilion border; often precipitated by topical corticosteroid abuse.
Carcinoid Syndrome:
Diff by episodic flushing associated with systemic signs: secretory diarrhea, wheezing, and tricuspid regurgitation murmurs; (+) elevated 24-hr 5-HIAA.
Management
General Measures (All Subtypes):
Trigger avoidance: Sun protection (broad-spectrum SPF ≥ 30 daily), avoid alcohol, hot beverages, and spicy foods.
Gentle skin care: Mild soap-free cleansers, avoidance of abrasive scrubs or astringents.
