Freckles (Ephelis, Ephelides, Freckles) are small tan or brown pigmented spots commonly found on the face, inherited as an autosomal dominant trait. They are particularly prominent in summer, and the development of the lesions is related to sun exposure.

bubble_chart Etiology

It is an autosomal dominant genetic disorder, where the same pattern of freckles can continuously appear in the same location across several generations in a family.

bubble_chart Pathological Changes

The basal cell layer exhibits increased melanin, but the number of melanocytes does not increase. The melanocytes in the lesion show stronger dopa positivity compared to those in the adjacent normal skin, with larger melanocytes and longer dendritic processes. In freckles, the number of melanocytes is higher, often appearing rod-shaped.

bubble_chart Clinical Manifestations

Freckles are more common in women and appear during childhood, typically starting to appear after the age of 6-7, becoming most prominent during adolescence. They tend to worsen with sun exposure in the summer and lighten in the winter.

The lesions are light yellow, tan, or brown spots, round, oval, or irregular in shape, ranging from the size of a pinhead to a grain. The spots do not merge and are asymptomatic, appearing on exposed areas of the skin, symmetrically distributed, especially on the face, including the nose, cheeks, back of the hands, and upper torso, but the palms, soles, and mucous membranes are not affected.

bubble_chart Treatment Measures

1. General Treatment: Avoid or reduce sun exposure. When going out in summer, apply sunscreen such as 2-5% titanium dioxide cream or 5% para-aminobenzoic acid ointment.

3. Corrosion Therapy: Such as 1-2% mercuric chloride alcohol or crystal paste. However, this method requires careful and close observation during topical application to avoid causing large-scale exfoliation.

4. Electrodesiccation: A treatment method that uses high-frequency current with higher voltage and lower current intensity to destroy pathological tissue. The needle-shaped treatment electrode is discharged 2-3 mm away from the lesion, and the electric spark destroys superficial tissue, which is called electrodesiccation. Freckles can also be treated with this method.

bubble_chart Differentiation

It should be differentiated from freckle-like nevi, which appear early, typically starting between 1 to 2 years of age. The lesions are densely distributed on the neck, chest, or other areas, often on one side. The affected skin is darker, does not fade in winter, and the color intensity is not influenced by sunlight.