Pigment Disorders
Idiopathic Guttate Hypomelanosis
IGH; "sun spots" (white)
Very common with age
No — you cannot catch it or spread it
Harmless; mostly a cosmetic concern
What Is It?
Idiopathic guttate hypomelanosis (IGH) causes small, flat, white spots on the skin, usually on the shins and forearms. "Idiopathic" means the exact cause is unknown, and "guttate" means drop-like. The spots are completely harmless and become more common with age.
Signs & Symptoms
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Small, flat, white or pale spots (2–5 mm)
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Well-defined, drop-like shape
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Most common on the shins and forearms
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Painless and without scale or itch
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More numerous with age and sun exposure
Why Does It Happen?
The exact cause isn't known, but the spots reflect a gradual, patchy loss of pigment (melanin) in small areas, associated with aging and long-term sun exposure. They are more noticeable on sun-exposed skin. IGH is NOT an infection, NOT contagious, and NOT a sign of a serious illness.
Treatment Options
IGH is harmless and needs no treatment. Because the spots are permanent, care focuses on prevention and, if desired, cosmetic camouflage.
LEAVE IT ALONE
The usual choice — the spots are harmless and stable.
SUN PROTECTION
Daily sunscreen limits contrast and helps prevent new spots.
COSMETIC CAMOUFLAGE
Self-tanner or makeup can blend spots with surrounding skin.
PROCEDURAL OPTIONS
Some in-office treatments are tried cosmetically, with mixed results.
Tips for Managing It at Home
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Use daily sunscreen to reduce contrast with normal skin
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Avoid tanning, which makes the white spots stand out more
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Moisturize dry skin on the shins and forearms
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Reassurance: these spots are harmless and expected with age
When to Call Your Provider
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Spots grow quickly, spread widely, or merge into large patches
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White areas become itchy, scaly, or inflamed
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You notice loss of color elsewhere (e.g., around eyes or mouth)
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You're unsure whether it's IGH or another condition
Sources & further reading
The information in this handout is based on general dermatology guidance from the reputable organizations below. These links are provided for patients who wish to read more from trusted sources.
DermNet. Idiopathic Guttate Hypomelanosis. https://dermnetnz.org/topics/idiopathic-guttate-hypomelanosis
Canadian Dermatology Association (CDA). Photoaging. https://dermatology.ca/public-patients/diseases-conditions/skin-conditions/photoaging/
Cleveland Clinic. Idiopathic Guttate Hypomelanosis. https://my.clevelandclinic.org/health/diseases/idiopathic-guttate-hypomelanosis
DermNet. Hypopigmentation. https://dermnetnz.org/topics/hypopigmentation
This handout is for general education and does not replace advice from your own provider. Always follow your provider’s specific instructions.
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