By Dr Nigel Stollery
By Dr Nigel Stollery
Venous varices, also known as venous lakes, are dark blue or violet papules caused by the dilatation of venules. They tend to occur in patients over the age of 50, usually on sun-exposed areas such as the ears and lips. They may be up to 1cm in diameter, are easily compressible and soft to the touch.
Venous varices are benign but may cause concern if they are mistaken for melanomas or basal cell carcinomas. Dermoscopy can be used to differentiate venous varices from melanocytic lesions, but if the diagnosis is in doubt the lesion should be excised.
Subconjunctival haemorrhage is caused by the rupture of a small conjunctival blood vessel. As the bulbar conjunctiva is lax, blood can track widely, leading to a strikingly red eye. The onset is usually painless.
The vast majority of subconjunctival haemorrhages occur spontaneously in otherwise healthy patients and the condition may be recurrent. Causes include:
• Trauma, especially from sporting injuries
• Viral conjunctivitis.
Subconjunctival haemorrhages do not usually require treatment, with the redness settling over one to two weeks.
Strawberry naevi may be present at birth but more commonly develop in the first few weeks of life. They usually start as a small, flat, red macule, which soon develops into a raised, strawberry-like nodule. The naevus increases in size as the child grows up to the age of 3-4 years after which it starts to regress.1 Full regression may take up to 10 years.2
Treatment is not usually required unless the lesion ulcerates and bleeds, obscures vision or interferes with the blood supply to a limb. In these cases plastic surgery, pulsed dye lasers or intralesional steroids may be used.
Recently, imiquimod has been found to be an effective treatment. However, it is generally reserved for patients with dangerous or proliferating lesions.3
Port wine stain
Superficial capillary naevi, or port wine stains, are the most common type of capillary malformation and are caused by a congenital defect that affects superficial blood vessels in the dermis.
As the patient grows, the stain increases in size and may also darken in colour. In some cases the lesion may become nodular. Superficial capillary naevi do not undergo natural regression.
In Sturge-Weber syndrome, port wine stains are associated with intracranial angiomas. These involve the leptomeninges and the skin of the face, typically in the ophthalmic and maxillary distributions of the trigeminal nerve, and can cause blindness, epilepsy, hemiplegia and mental retardation.
If the stain is large or on an area such as the face, the patient is usually treated with pulse dye lasers.4 Increasingly younger patients are now being treated with this therapy, often at around 12 months old, and referral before this age is appropriate.5
Naevus anaemicus lesions are white macules caused by localised vasoconstriction. They may be mistaken for vitiligo or an area of hypopigmentation. The diagnosis can be confirmed by applying pressure to the surrounding area, which will blanch, causing the macule to ‘disappear' temporarily. Alternatively, if the skin is rubbed the surrounding area will redden but the pale area will remain unchanged.
Naevus anaemicus is not a progressive condition and the patient can be reassured that the macule will not increase in size.
A subungual haematoma is formed when bleeding occurs under a nail. This is usually the result of trauma to the toe, such as a direct blow or repeated trauma from tight shoes. Discolouration is visible through the nail, which can appear black.
As there is limited room for expansion, the condition can be very painful. The pressure can be released by creating a hole through the nail.
An easy way of doing this is to heat the end of an unfolded paperclip, which can then be used to burn a small hole through the nail, allowing the blood to drain.
The most serious differential diagnosis is subungual malignant melanoma, and patients should be referred for biopsy if the diagnosis is uncertain.Venous varix Subconjunctival haemorrhage Strawberry naevus Port wine stain Naevus anaemicus Subungual haematoma Author
Dr Nigel Stollery
MB BS DPD
GP, Kibworth, Leicestershire and clinical assistant in dermatology, Leicester Royal Infirmary