What is the likely cause of persistent periorbital hyperpigmentation in a 4‑year‑old child whose father also has it, and what evaluation and management are recommended?

Periorbital Hyperpigmentation in a 4-Year-Old with Family History

The most likely cause is hereditary/constitutional periorbital hyperpigmentation, which is a benign condition that runs in families and requires no treatment beyond reassurance and sun protection. 1, 2

Primary Diagnosis: Constitutional (Hereditary) Periorbital Hyperpigmentation

The presence of identical dark circles in both father and child strongly indicates constitutional periorbital hyperpigmentation, which is the most common form (51.5% of cases) and follows a familial pattern. 3 This benign condition typically:

• Appears early in life and persists throughout adulthood 1
• Shows autosomal dominant inheritance patterns in many families 3
• Affects all racial groups but is more prominent in darker skin types 2
• Involves primarily dermal melanin deposition (60.5% of cases) 3

Critical Differential to Exclude: Peutz-Jeghers Syndrome

Before providing reassurance, you must exclude Peutz-Jeghers syndrome (PJS), a serious autosomal dominant condition that presents with periorbital pigmentation. 4 Key distinguishing features:

PJS characteristics that would require urgent referral:

• Pigmented macules on the buccal mucosa (66% of PJS patients) - this is pathognomonic and never seen in simple constitutional hyperpigmentation 4
• Dark brown or blue-brown macules 1-5mm in size on the vermilion border of lips (94% of PJS) 4
• Pigmentation on hands (74%) and feet (62%) 4
• History of intestinal intussusception or rectal bleeding 4
• Gastrointestinal polyps leading to symptoms by ages 10-30 5

Examination essentials:

• Inspect the oral mucosa carefully - buccal pigmentation distinguishes PJS from benign causes 4
• Check lips, hands, feet, and perianal area for additional pigmented lesions 4
• Ask about gastrointestinal symptoms (abdominal pain, bleeding, intussusception) 4

If any oral mucosal pigmentation or GI symptoms are present, refer immediately to a tertiary cancer center or pediatric gastroenterology for genetic testing. 4

Evaluation Algorithm

Step 1: Rule out systemic causes (though unlikely at age 4)

• Assess for atopic dermatitis or allergic contact dermatitis causing postinflammatory hyperpigmentation 1, 3
• Check for periorbital edema suggesting allergic or atopic disease 1
• Examine for signs of eye rubbing (common in atopy, seen in 32.5% of POH cases) 3

Step 2: Assess for secondary factors

• Sleep patterns (inadequate sleep in 40% of POH cases) 3
• Eye rubbing habits 3
• Sun exposure history 2

Step 3: Wood's lamp examination (if available)

• Helps differentiate epidermal (enhances under Wood's lamp) from dermal pigmentation 3
• Dermal pigmentation is more common (60.5%) and more resistant to treatment 3

Management Approach

For constitutional periorbital hyperpigmentation (after excluding PJS):

Primary recommendation: Reassurance and sun protection only. 2

• Explain this is a benign, inherited trait that poses no health risk 1, 2
• Emphasize that treatment is unnecessary and purely cosmetic 1
• Strict sun protection is the cornerstone of management to prevent worsening 2
• Avoid eye rubbing if present 3
• Ensure adequate sleep 3

Treatment considerations (generally deferred until adolescence/adulthood):

• Topical treatments (hydroquinone, kojic acid, azelaic acid, retinoids) are not recommended in young children due to safety concerns and lack of efficacy data 1, 6
• Chemical peels and laser therapy carry significant risk of worsening pigmentation, especially in darker skin types 2, 6
• Most treatments show limited success and high recurrence rates 6

Common Pitfalls to Avoid

• Missing oral mucosal examination - this is the critical step to exclude PJS 4
• Initiating cosmetic treatments in a 4-year-old - these are inappropriate at this age and carry risks 2
• Failing to provide adequate sun protection counseling 2
• Not recognizing that constitutional POH typically worsens over time without intervention, but remains benign 2

Follow-Up

• No specific follow-up needed if examination is normal and PJS excluded 1
• Reassess if new symptoms develop (GI complaints, additional pigmented lesions) 4
• Revisit cosmetic concerns in adolescence if desired, when safer treatment options may be considered 2