Larva migrans | Leprosy | Leukoderma (go to vitiligo) | Leukoplakia, oral | Lice (go to pediculosis) | Lichen amyloidosis | Lichen planus | Lichen sclerosus et atrophicus | Lichen simplex chronicus | Lipoma | Lupus erythematosus

Larva migrans also known as creeping eruption is a larval infestation of the superficial skin. It occurs most commonly in the tropics and subtropics and usually affects travelers to and from these areas.

Cause

• Larva migrans is caused by the larvae of the cat or dog hookworm. The larvae enter by biting the bare skin of people walking or sitting on warm, humid sand. Children may be infested while playing in sandboxes. The larvae cannot complete its life-cycle in the skin and spends its whole life wandering within the superficial layers of the skin until it dies some 4 - 6 weeks later.

  Symptoms

• Slightly raised red serpentine tracts caused by the wandering larvae.
• Itching.

  Larva migrans. Click on image for larger view

  Complications

• Secondary bacterial infection.

  What you can do

• You should consult a doctor.

  What the doctor may do

• Prescribe oral thiabendazole or albendazole or apply liquid nitrogen to the advancing end of the serpentine tracts.
• Treat secondary bacterial infections with antibiotics.

TOP

Leprosy or Hansen's disease is chronic contagious skin disease that damages the nerves supplying the skin and muscles, causing loss of sensation, muscle wasting, blindness and deformities. It is seen mainly in the tropics and subtropics.

Cause

• Leprosy is caused by the Mycobacterium leprae bacteria which attacks the skin, mucous membranes and nerves. Infection is acquired through inhalation or ingestion of infected droplets and the symptoms may take 2 - 6 years to develop.

   

  Predisposing factors

• Living in an endemic areas (areas known to have large numbers of leprosy cases).
• Family history of leprosy.
• Malnutrition.
• Over-crowding.

   

  Symptoms
  The symptoms depend on the stage and degree of immunity of the person. Leprosy is divided into the following stages:

   

• Indeterminate leprosy

   

  • This is the earliest stage of leprosy.
  • It causes reddish or hypopigmented (lightened) patches.
  • There may be some alteration of sensation.
  • This stage is often overlooked or neglected until leprosy progresses into the more advanced forms below.

   

• Tuberculoid leprosy

   

  • This occurs in people with higher immunity.
  • It causes pinkish or hypopigmented (lightened) patches with red, slightly raised borders.
  • Tendency to occur in rings.
  • Usually one to a few patches are present.
  • Loss of sensation.
  • Affected nerves become thickened (usually best seen on the neck and felt around the elbows and knees) or damaged, leading to paralysis (claw hand, wrist drop., etc).

   

• Lepromatous leprosy

   

  • This form occurs in people with low immunity.
  • Causes shiny hypopigmented (lightened) patches or dull red papules (bumps), nodules (larger swellings) or plagues (raised patches).
  • Multiple (unlike tuberculoid leprosy) and symmetrically distributed on the body.
  • Diffuse infiltration of the skin on the face with loss of eyebrows and eyelashes (causing leonine facies) and swelling of the legs and feet.
  • Destruction of the nasal cartilage, causing saddle-shaped deformity, destruction of the larynx (voice-box), causing hoarseness.
  • Eye problems (iritis, keratitis, episcleritis).
  • Nerve damage causing paresthesia (pins and needles) and paralysis.

   

• Borderline leprosy

   

  • This is an intermediate form between tuberculoid and lepromatous leprosy. It is called borderline tuberculoid leprosy when it resembles tuberculoid leprosy more and borderline lepromatous leprosy when it resembles lepromatous leprosy more.
  • Pins and needles or numbness of the hands and feet as the disease progresses.

   

  Lepromatous leprosy. Click on image for larger view

  Complications

• Ulcers and severe burns occur because the withdrawal response to pain that protects the body against injury is lost.
• Muscle weakness, clawing deformity of the hands and foot drop develop when the nerves supplying the muscles are damaged.
• Nerve damage affects corneal sensation and the ability of the eyelids to close, resulting in corneal ulceration and blindness.
• Destruction and collapse of the cartilage of the nose, causing a saddle-shaped deformity.
• Destruction of the larynx, causing hoarseness.
• Destruction of bones, leading to deformity and shortening of the digits.
• Squamous cell cancer may develop in chronic skin ulcers.

  What you can do

• You should consult a doctor. Early treatment prevents complications and transmission to other family members.

  What the doctor may do

• Confirm the diagnosis with split skin smears and skin biopsies.
• Determine the type of leprosy because the type and duration of treatment is different.
• Treat with a combination of antibiotics for several months to years.
• Screen and follow-up family contacts.

TOP

Oral leukoplakia refers to a whitish thickening on the lips, tongue and inside of the mouth.

Cause

• Chronic irritation caused by smoking, tobacco and betel nut chewing, spicy foods, alcohol, biting of the lips and poorly fitting dentures.
• Infection by certain types of the wart or human papilloma virus (HPV 11 and 16).
• Infection by the Epstein Barr virus which causes a special form of leukoplakia known as oral hairy leukoplakia.

   

  Symptoms

• White patch which cannot be scraped off (contrast with oral candidiasis).
• Oral hairy leukoplakia is usually seen in homosexual HIV infected patients.

  Oral leukoplakia. Click on image for larger view

  Complications

• May transform into a squamous cell cancer.
• Secondary infection by candida is common (see candidiasis).

  What you can do

• You should consult a doctor.
• Cut down on smoking, alcohol consumption and spicy foods.
• See a dentist to have the dentures remade.

  What the doctor may do

• Examine scrapings for the presence of candidiasis.
• Perform a biopsy to confirm the diagnosis.
• Remove the affected area surgically.
• Treat with electrosurgery, carbon dioxide laser or liquid nitrogen.
• Treat or eliminate the underlying cause.

TOP

This is an extremely itchy condition caused by the deposition of an abnormal protein called amyloid in the skin. It is more common in middle-aged oriental women.

Cause

• Degenerative process affecting the basal cells of the epidermis in which keratin filaments are converted to a substance known as amyloid. Why this happens is not known.

  Symptoms

• Extremely itchy reddish brown papules (bumps) on the shins.
• Macular amyloidosis is another form in which the skin has a grey rippled appearance. It usually affects the upper back and is usually not itchy.

  Lichen amyloidosis. Click on image for larger view

  What you can do

• You should consult a doctor.
• Take antihistamines to relieve itching.
• Avoid scratching or rubbing the skin with rough objects as it usually worsens the condition in the long run.

   

  What the doctor may do

• Perform a skin biopsy to confirm the diagnosis.
• Prescribe topical steroids.
• Prescribe oral retinoids or systemic steroids in resistant cases.
• Treat with phototherapy (light treatment).

TOP

Lichen planus is an extremely itchy skin condition of unknown cause. It occurs at any age and may last for months to years.

Cause

• Unknown, may be autoimmune in which the immune system attacks the skin cells as though they were foreign.
• Allergy - Drugs such as chloroquine (antimalarial drug), gold (sometimes used in the treatment of rheumatoid arthritis), captopril (used in the treatment of high blood pressure), streptomycin (anti-tuberculosis drug), lithium (used in the treatment of manic-depressive states) and contact with colour developers may cause a lichen planus-like eruption.

  Symptoms

• Shiny, flat-topped pink or purplish papules (bumps) which often have white lines known as Wickham's striae crisscrossing their surface.
• The rash usually occurs on the front of the wrists, on the forearms, the lower legs, the ankles, the lower back, the genital area, around the umbilicus (navel) and in a line along scratch marks.
• The rash is usually extremely itchy.
• The rash usually clears by 18 months but can persist for years in some patients.
• Dark patches often remain after the rash has cleared and these may take several months to clear.
• In some individuals the rash becomes very thick and scaly. This form of lichen planus is called hypertrophic lichen planus and is more persistent. This form usually occurs on the shins.
• White lace-like patterns can be seen on the inside of the cheeks and the tongue in 50% of cases. Sometimes ulcers develop.
• Lichen planus may occasionally affect the nail causing minor surface changes or in some cases, destruction or shedding of the entire nail.
• Lichen planopilaris is a form of lichen planus that affects the hair. It may cause scarring alopecia.
• Lichen nitidus is a form of lichen planus that causes tiny pink or skin coloured papules on the penis and extremities. Unlike lichen planus, lichen nitidus is not itchy.

  Lichen planus. Click on image for larger view

  What you can do

• You should consult a doctor.
• Take antihistamines to relieve itching.

  What the doctor may do

• Perform a skin biopsy to confirm the diagnosis.
• Prescribe a strong topical steroid or in very severe cases, even systemic steroids.
• Prescribe antihistamines.
• Eliminate the cause.

TOP

Lichen sclerosus et atrophicus is an uncommon skin condition that may affect children and middle-aged adults. It is slightly more common in women. It occurs in two forms:

• Genital form
• Non-genital form

  Cause

• Unknown.

  Symptoms

• Genital form

   

  • Ivory white atrophic (thinned), shrunken skin affecting the vulva (vaginal lips) and the skin around the anus, causing a narrowing of the vaginal opening and anus, respectively. Telangiectasias (broken capillaries) and purpura (haemorrhagic spots) are often present.
  • Similar changes may affect the inner foreskin and glans penis (penile head), causing phimosis (difficulty retracting the foreskin) and narrowing of the urethral opening in males.
  • Itching, burning, dyspareunia (painful intercourse) and difficulty urinating due to the narrowing of the urethral opening in males.

   

• Non-genital form

   

  • Clusters of ivory white spots which are often surrounded by a red halo. The individual spots are flat topped and may be level with the skin, slightly elevated or depressed. The skin pores are often dilated and filled by keratin plugs.
  • They usually occur on the trunk, neck, armpits and front of the wrists.

  Complications

• Superimposed candidiasis (yeast infection).
• Squamous cell cancer may develop in long-standing cases of lichen sclerosus et atrophicus affecting the vulva.

  What you can do

• You should consult a doctor.
• Take antihistamines to relieve itching. Do not scratch.

  What the doctor may do

• Perform a skin biopsy to confirm the diagnosis.
• Prescribe topical steroids.
• Treat the complications.

TOP

Lichen simplex chronicus refers to a thickening of the skin caused by repeated scratching. It is also known as neurodermatitis because scratching is more prominent under stress.

Cause

• An area of skin that is hypersensitive and gratifying to scratch. The increased sensitivity of the skin may be partly explained by the finding of enlarged sensory nerve endings in the skin.

  Symptoms

• Thickened patch usually on areas within reach of itchy fingers such as the back and sides of the neck, the scalp, the limbs, ankles and genitals.
• Severe itching which comes on suddenly, causing the person to scratch. The heel is often used to rub itchy areas on the feet.

  Lichen simplex chronicus on the side of the ankle. Click on image for larger view

  What you can do

• You should consult a doctor.
• Stop scratching or rubbing as this perpetuates the problem. Unfortunately, scratching is so satisfying that stopping becomes difficult.
• Apply moisturisers to soothe the skin.
• Take antihistamines to reduce itching.

  What the doctor may do

• Prescribe strong topical steroids with or without occlusion.
• Give intralesional steroids.
• Prescribe tranquilisers in tense individuals.

TOP

Lipomas are harmless rubbery skin swellings occuring anywhere on the body, particularly on the neck, shoulders, back and abdomen.

Cause

• Non-cancerous overgrowth of fatty tissue in the skin.

  Symptoms

• Soft, lobulated, rubbery swellings 1 - 2 cm in size or larger under a normal looking skin.
• The swellings can be moved within the skin.
• Painless.
• May be solitary or multiple.

  What you can do

• You should consult a doctor to confirm the diagnosis.

  What the doctor may do

• Excise or remove by liposuction (suction removal of fat).

TOP

Lupus erythematosus (LE) is a disorder of the connective tissues. The term, cutaneous lupus erythematosus (cutaneous LE) is used when LE affects the skin alone and systemic lupus erythematosus (SLE) when other parts of the body such as the joints, muscle, kidneys, lungs, the nervous system and other internal organs are affected. Women are more commonly affected. Discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE) are the most common varieties of cutaneous LE.

Causes

• Autoimmune disorder (self-allergy) caused by the immune system attacking the body tissue as though it was foreign.
• Drug induced LE due to drugs such as hydralazine, procaineamide and isoniazid.

  Symptoms
  

• Discoid lupus erythematosus (DLE)

   

  • Well-defined red, scaly, scarred patches with telangiectasias (threadlike veins). Usually occur on the sun-exposed areas, especially the face, upper back, "v" of the neck, backs of the hands and occasionally on the scalp where it may cause a scarring alopecia.
  • About 5% DLE cases go on to develop SLE.

   

• Subacute cutaneous lupus erythematosus (SCLE)

   

  • Red scaly psoriasis-like patches.
  • Tendency to occur in rings.
  • There may be mild fever and malaise of feeling of illness).

   

• Systemic lupus erythematosus (SLE)

   

  • Red butterfly rash on the cheeks and across the bridge of the nose.
  • Rashes are characteristically worsened or precipitated by exposure to sunlight.
  • Telangiectasias (broken blood vessels) on the palms, fingers and nailfolds.
  • Vasculitis, urticarial vasculitis and Raynaud's phenomenon (blanching of the fingers and toes in cold weather, followed by numbness, a bluish colour, then redness on rewarming.
  • Telogen effluvium (diffuse hairloss).
  • Arthritis.
  • SLE may also affect the kidneys, lungs, liver, blood and the nervous system.

  Discoid lupus erythematosus. Click on image for larger view

  Complications

• In SLE, death may result from involvement of other vital organs, especially the kidneys and central nervous system.
• Squamous cell cancers may develop in areas of DLE.

  What you can do

• You should consult a doctor.
• Protect yourself against sunlight because it makes LE worse (see sun protection).

  What the doctor may do

• Perform a skin biopsy to confirm the diagnosis.
• Test the blood for the presence of antinuclear and anti-DNA antibodies.
• Treat with topical steroids, intralesional steroids, dapsone (a drug used to treat leprosy) and antimalarial medicines (chloroquine and hydroxychloroquine). SLE may require treatment with oral steroids and immunosuppressive drugs such as azathioprine and cyclophosphamide.
• Reinforce the importance of sun protection.

TOP