Translation guide
A lentigo is a small, flat, brown spot on the skin, often caused by sun exposure. In Japanese, the most common equivalent is しみ (shimi), which broadly covers age spots, sun spots, and freckles. Medical contexts may use 黒子 (hokuro) or the loanword レンティゴ (rentigo).
The speaker wants to refer to a small, flat, brown skin spot, typically from sun exposure or aging, in everyday conversation.
The most common and natural word for any flat brown spot on the skin, including age spots, sun spots, and freckles. Used in daily conversation and cosmetics.
顔にしみができた。
I got a brown spot on my face.
このしみを消したい。
I want to get rid of this spot.
Katakana version of しみ, often used in cosmetics advertising or product names for emphasis.
シミ対策クリーム
anti-spot cream
The speaker needs a precise medical term, such as in a dermatology context.
Technically means 'mole' or 'nevus', but can be used for lentigo in medical contexts. Be aware that ほくろ usually implies a raised or darker mole, not necessarily a flat lentigo.
In everyday language, ほくろ is understood as a mole, not a flat spot. Use しみ for flat brown spots.
この黒子は良性です。
This mole is benign.
Direct loanword from English 'lentigo', used only in specialized medical literature. Not understood by general public.
老人性レンティゴは加齢による色素斑です。
Senile lentigo is a pigmented spot due to aging.
The speaker wants to specify a spot caused by sun exposure, often on sun-exposed areas.
Medical term for solar lentigo. Literally 'sunlight-induced black spot'. Used in dermatology.
日光性黒子は紫外線が原因です。
Solar lentigo is caused by UV rays.
Shorter variant of 日光性黒子, also medical.
日光黒子の治療について
About treatment of solar lentigo
しみ (shimi) is a general term for flat brown spots (age spots, sun spots, freckles). そばかす (sobakasu) specifically means freckles, often genetic and appearing in youth. ほくろ (hokuro) means mole, usually raised or darker. For lentigo, しみ is the best everyday word.
彼女はそばかすがかわいい。
Her freckles are cute.
背中に大きなほくろがある。
I have a big mole on my back.
The English word 'lentigo' is highly technical. In Japanese, using レンティゴ will not be understood outside medical contexts. Always prefer しみ for general use.