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Occupational dermatitis | Onychogryposis | Onycholysis | Onychomycosis | Ota's naevus (go to naevus of Ota)

OCCUPATIONAL DERMATITIS

This is a type of contact dermatitis that is caused by or aggravated by the work environment. It may affect workers in any industry but is more common in those working in the construction, electrical and engineering industries.

    Cause

  • Allergic contact dermatitis.
  • Irritant contact dermatitis.
  • Chemical burns from acids, eg., chromic acid (used in chrome plating).
  • Inflammation of the follicles (folliculitis and chloracne).

    Symptoms

  • Eczema.
     
    • During acute stages, there is weeping, blistering or red papules (pimply bumps).
    • During chronic stages, there is dryness, redness, scaling, lichenification (leathery thickening of the skin with accentuation of the skin markings) and hyperpigmentation.
     
  • Folliculitis and acneiform eruption, eg., chloracne.
  • Lichen planus-like eruption due to colour developers.
  • Ulcers from chemical burns (eg., chromic acid burns in chrome plating workers).

    Complications

  • Secondary bacterial infection.

    When you should suspect occupational contact dermatitis

  • Rash appears after starting work or after new products are introduced into the workplace.
  • Colleagues are also affected.
  • The rash improves during weekends and holidays and worsens after commencing work.

    What you can do

  • You should consult a doctor.
  • Take antihistamines to relieve itching.
  • Use barrier creams to protect the skin.
  • Wear protective gloves and aprons.
  • Wash carefully.

    What the doctor may do

  • Determine the cause using patch tests.
  • Treat the dermatitis with topical or systemic steroids.
  • Recommend changes to the work environment such as providing proper ventilation, protective shields to prevent splashing and adequate cleansing facilities.
  • Recommend the use of alternative chemicals.
  • Recommend a change of occupation in some cases.
  • Educate the patient on proper working and cleansing habits.
  • Notify the country's industrial health or public health department who will investigate the case, visit the workplace and make recommendations.

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ONYCHOGRYPOSIS

This is an unusual horn-like overgrowth of the nails, usually the toenails.

    Causes

  • Trauma.
  • Tight shoes.
  • Hereditary.
  • Circulatory problems.

    Symptoms

  • The nail becomes curved, discoloured and thickened rather like a ram's horn.

    What you can do

  • Wear proper fitting shoes.
  • Consuly a doctor.
  • Have a chiropodist trim the hard deformed nail regularly.

    What the doctor may do

  • Remove the abnormal nail surgically.

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ONYCHOLYSIS

Onycholysis refers to a separation of the nail plate from the nail bed.

    Causes

  • Excessive contact with water.
  • Trauma from tight shoes and poor manicuring.
  • Allergy to nail cosmetics.
  • Drugs such as tetracycline and thiazide diuretics which may cause photo-onycholysis (sun-activated onycholysis).
  • Fungal infection (see onychomycosis).
  • Skin disorders such as psoriasis and lichen planus.
  • Overactive or underactive thyroid gland.
  • Circulatory problems.
  • Idiopathic (of unknown cause).

    Symptoms

  • Lifting of the nail plate which becomes white and opaque initially.
  • Eventually, dirt accumulates underneath the nail plate which becomes thickened and discoloured.

    Complications

  • Secondary invasion by fungi, especially Candida albicans and other yeastlike fungi.
  • Secondary bacterial infection.

    What you can do

  • You should consult a doctor.
  • Cut back the nail so that the area underneath can be cleaned.
  • Immerse the finger into mild detergent solution after cutting the nail back and gently clean away any accumulated debris. Do not use nail files of toothpicks as this causes more separation.
  • After cleansing, dry the area well.
  • Minimise contact with water (see hand eczema).

    What the doctor may do

  • Determine the cause and treat accordingly.

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ONYCHOMYCOSIS

Onychomycosis (tinea ungium) is a fungal infection of the nails. It needs to be differentiated from psoriasis, eczema of the fingers/toes and candidal paronychia which may all produce similar nail changes.

    Cause

  • Fungi, including Candida albicans and other yeastlike fungi.

    Symptoms

  • Opaque white patches at the sides of the free edge of the nail which becomes yellow and then brown with time.
  • Keratin (dead horn cells) and debris accumulate under the nails.
  • Nail plate becomes discoloured, thickened, deformed and brittle and may loosen.
  • Paronychia (inflamed nail folds) commonly accompanies onychomycosis caused by Candida albicans and other yeasts.

      Tinea ungium.
    Click on image for larger view 

    Complications

  • Secondary bacterial infection and paronychia.
  • What you can do
  • You should consult a doctor as oral antifungals are required.
  • Keep the nails short.
  • Wear proper fitting shoes if the toe nails are involved.
  • Adopt the same measures for tinea pedis.

    What the doctor may do

  • Take nail clippings and/debris for microscopic examination and/or culture for fungus.
  • Prescribe oral antifungal drugs - 6 to 8 months for fingernail infections and 12 to 18 months for toenail infections. The duration of treatment is shorter with the newer antifungal agents.
  • Removal of the nail may be helpful in very resistant cases.

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