Blue naevus is smooth, slightly raised and appears blue
- Smooth, round, slightly raised, blue papules. Less than 0.5mm in diameter.
- May occur anywhere on the body. Common on the face, and backs of hands and feet.
- Dermoscopy - homogenous steely-blue colour. No network or other features.
- Watch for sudden increase in size or ulceration.
- Type of mole that forms when melanocytes collect in the mid- to lower dermis.
- Due to its depth and the effect on preferential absorption of long wavelengths of light, the lesion appears blue.
- Frequently present in the teens but may occur at any age. Usually persist throughout life.
- More common in women and in Asian populations.
- Benign lesions that rarely show malignant change.
- No treatment required unless for cosmetic reasons or concern of malignancy.
- Surgical excision/biopsy.
Venous lake tends to occur in men over the age of 50
- Compressible, well-defined blue, red or purple papules with smooth surface.
- Blanches on pressure.
- Up to 1cm in diameter.
- Usually symptomless but may sometimes bleed.
- Dermoscopy - homogenous reddish-blue or reddish-black colour. No pigment structures.
- Angioma due to dilated venules.
- Tends to occur on lips or sun-damaged skin.
- Usually present over the age of 50 and more common in men.
- No treatment necessary unless cosmetic, bleeding or diagnostic concerns.
- Biopsy if in doubt about the diagnosis.
- Surgical excision.
- Cryotherapy, electrosurgery or sclerotherapy.
- Laser therapy; argon laser and infra-red coagulator may result in scarring.
Contributed by Dr Jean Watkins, a sessional GP in Hampshire.