An 8-Year-Old Girl with Lesions on Her Arms

Differential Diagnosis

• Common acquired nevus
• Ephelides
• Lentigo simplex
• Tinea versicolor

Diagnosis

This patient was diagnosed with lentigo simplex— a common benign, hyperpigmented macule located anywhere on the body. These lentigines generally occur early in life (even at birth). They result from a mild increase in the number of normal melanocytes in the epidermis producing increased amounts of melanin.

Learnings/What to Look for

• Well-circumscribed, symmetric, homogeneous, light brown to black macules, usually smaller than 5 mm in size, are seen
• Distribution may be anywhere on the trunk, extremities, genitals, and mucous membranes
• Lentigines found on mucous membranes can appear irregular with increased size, irregular borders, and heterogeneous pigmentation
• Lentigo simplex may evolve into junctional nevi but are not thought to evolve into melanoma
• Macules differ from solar lentigines in that they appear earlier in life on non-sun-exposed skin

Pearls for Urgent Care Management and Considerations or Transfer

• Lentigo complex is a benign lesion; no treatment is necessary
• Referral to a dermatologist for a baseline exam and subsequent follow-up is warranted

Acknowledgment: Images and case courtesy of VisualDx (www.VisualDx.com/JUCM).