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Naevus of OTA | Naevus sebaceum | Napkin dermatitis | Nappy rash (go to napkin dermatitis) | Necrobiosis lipoidica | Neurofibroma | Neuorodermatitis (go to lichen simplex chronicus) | Nummular dermatitis or discoid eczema

NAEVUS OF OTA

This is a type of pigmented birthmark that is more common in Orientals and Blacks. It may occur at birth or during the first two decades of life and persists indefinitely. Women are more commonly affected.

    Cause

  • Non-cancerous proliferation of melanocytes (pigment cells) in the dermis (deeper layer of the skin).

    Symptoms

  • Blue-black or grey pigmentation around one eye.
  • The sclera (white of the eye) may be afected, as well
      Naevus of Ota.
    Click on image for larger view
    What you can do
  • Nothing, live with it.
  • Use cosmetic camouflage.
  • Consult a doctor for treatment

    What the doctor may do

  • Treat with one of the pigment lasers.

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NAEVUS SEBACEUM

This is a developmental abnormality affecting the scalp.

    Cause

  • Developmental abnormality arising from the sebaceous glands.

    Symptoms

  • Appears at or shortly after birth
  • Yellowish orange elevated patch on the scalp associated with some degree of hairloss.

    Complications

  • May develop into basal cell or some other cancers.

    What you can do

  • You should consult a doctor for removal because of the cancer risk.

    What the doctor may do

  • Excise the naevus or destroy with electrosurgery or the carbon dioxide laser.

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NAPKIN DERMATITIS

Napkin dermatitis, diaper dermatitis or nappy rash is a common skin problem in infants and young children who are not yet potty trained.

    Causes

  • Prolonged contact of the skin with urine and faeces in soiled nappies is the main cause.
  • Irritation caused by antiseptics and disinfectants used for cleaning nappies.
  • Skin conditions such as seborrhoeic dermatitis, atopic dermatitis and psoriasis affecting the napkin area.

    Symptoms

  • Redness and swelling or blistering and ulceration in severe cases.
  • In chronic cases, the area becomes red and scaly.
  • Affects the napkin area but typically spares the apex of the groin crease which does not come into direct contact with soiled nappies.

    Complications

  • The moist environment encourages the development of secondary candidiasis (yeast infection).
    What you can do
  • Prevention is better than cure and the most important strategy is to keep the area clean and dry.
  • Apply wet compresses to reduce inflammation.
  • Cleanse with water after each passage of urine or stool, pat dry and apply a water repellent formula such as white soft paraffin, silicone cream or zinc oxide ointment.
  • Expose to air as often as possible.
  • Change nappies as soon as they are soiled.
  • Wash nappies thoroughly to remove antiseptics and detergents. It helps to add an ounce of household vinegar to a gallon to water during the final rinse to adjust the pH closer to the skin pH.
  • Consult a doctor if it there is no improvement. It may indicate candidiasis or underlying skin disease such as seborrhoeic dermatitis, atopic dermatitis or psoriasis.

    What the doctor may do

  • Prescribe a mild topical steroids.
  • Take skin scrapings to exclude candidiasis.
  • Prescribe topical antifungals if candidiasis is present.

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NECROBIOSIS LIPOIDICA

This is a degenerative skin condition that is often, though not always, associated with diabetes.

    Cause
  • Inflammation and degeneration of collagen tissues in the skin, possibly as a result of diabetes affecting the small blood vessels in the skin..

    Symptoms

  • Begins as one or more dusky red plaques (raised patches) on the shins.
  • These enlarge in size and the centre becomes slightly depressed, thinned and waxy yellow in colour. Telangiectasias (broken capillaries) can usually be seen through the thinned skin.
      Necrobiosis lipoidica.
    Click on image for larger view
    Complication
  • The skin is fragile and can be easily traumatised, leading to ulcers.

    What you can do

  • You should consult a doctor.
  • Protect the area from injury.
  • Make sure that your diabetes is well controlled.

    What the doctor may do

  • Perform a skin biopsy to confirm the diagnosis, if necessary.
  • Perform blood and urine tests to exclude diabetes unless already diagnosed.
  • Control diabetes with drugs and dietary advice.
  • Treat with topical steroids or intralesional steroids.
  • Prescribe oral pentoxifylline which helps to improve blood circulation.

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NEUROFIBROMA

Neurofibromas are soft skin growths arising from the nerve sheath. They may be solitary or multiple. The term neurofibromatosis or von Recklinghausen's disease is used when neurofibromas are multiple and associated with other abnormalities (see below). Neurofibromatosis or von Recklinghausen's disease is inherited and usually occurs during adolescence whereas solitary neurofibromas usually occur in adults.

    Causes

  • Non-cancerous or benign growth of the nerve sheath. Neurofibromatosis or von Recklinhausen's disease is inherited in an autosomal dominant fashion which means that only one parent need to be affected and the offsprings have a 50% chance of inheriting and developing the disorder.

    Symptoms

  • Single or multiple, soft, skin-coloured nodules (swellings).
  • The nodule can be pressed into the skin with the finger tip. Doctors call this the button-hole sign and this is diagnostic of neurofibromas.
  • The nodules increase in size over time and may become pedunculated.
  • Occasionally, the nodules may form large folded or pendulous masses known as plexifom neurofibromas. Sometimes a whole limb is affected, causing elephantiasis.
  • Multiple cafe-au-lait patches (which means "coffee with milk" patches), freckles in the armpits and groins and kyphoscoliosis (curvature of the spine) are other signs associated with von Recklinghausen's disease.
  • Neurofibromas may sometimes affect the central nervous system, optic nerves of the eyes, the eight nerve (which) and spinal column.

    Complications
  • Severe cosmetic disfigurement, especially if there are hundreds or thousands of neurofibromas.
  • Cancerous change may occasionally occur in plexiform neurofibromas.
  • Bone and spine curvatures (eg., kyphoscoliosis).

    What you can do

  • You should consult a doctor.

    What the doctor may do

  • Perform a skin biopsy to confirm the diagnosis.
  • Refer you to a ophthalmologist for a slit-light examination of the eyes
  • Excise disfiguring swellings or those that have increased rapidly in size or are painful.
  • Provide genetic counseling for patients with von Recklinghausen's disease.
  • Follow up cases of plexiform neurofibromas so that any cancerous change can be detected early.

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NUMMULAR DERMATITIS OR DISCOID ECZEMA

Nummular (nummulus in Latin means coin-shaped) dermatitis or discoid eczema causes coin-shaped patches of eczema. It occurs more commonly outside the 30 - 50 year age group.

    Causes

  • Usually regarded as a type of endogenous or constitutional eczema. May be a variety of atopic dermatitis in children.
  • May be caused by allergy to nickel (found in metals) and chromates (in cement).

    Aggravating factors
  • Xerosis or dry skin.
  • Dry winters.
  • Irritation from rough fabrics.
  • Stress.

    Symptoms

  • Starts as small blisters or papules (bumps) which rapidly join to form plaques (elevated patches).
  • The plaques are typically round or coin-shaped and often become weepy and crusted.
  • They usually affect the front of the legs, back of the forearms and buttocks and occasionally, the trunk, as well.
  • The surrounding skin is may be dry or xerotic (see xerosis).
  • Itching is often severe.
      Nummular dermatitis or discoid eczema.
    Click on image for larger view
    Complications
  • Secondary bacterial infection.
  • Tendency to recur.

    What you can do

  • You should consult a doctor.
  • Take antihistamines to relieve itching.
  • Avoid scratching.
  • Keep the skin well moisturised because dry skin increases the likelihood of relapse.
  • Avoid woolen and rough textured fabrics.

    What the doctor may do

  • Prescribe topical or in severe cases, even systemic steroids. Intralesional steroids may be used to treat very resistant patches.
  • Prescribe antibiotics for secondary bacterial infection.
  • Phototherapy (UV-B or PUVA) may be used to treat severe and widespread cases.

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