Scabies and Impetigo

Marlyn Mary Mathew Background

• Scabies is an intensely pruritic, highly contagious infestation of the skin • Originally, scabies was a term used by the Romans to denote any pruritic skin disease. • In the 17th century, Giovanni Cosimo Bonomo identified the mite as one cause of scabies. Causes

• The causative agent for this disease is Sarcoptes scabiei. • The mites that cause scabies burrow into the skin and deposit their eggs, forming a burrow that looks like a pencil mark. • Eggs mature in 21 days. The itchy rash is an allergic response to the mite.

Symptoms

• Itching, especially at night. • Rashes, especially between the fingers. • Sores (abrasions) on the skin from scratching and digging. • Thin, pencil-mark lines on the skin.

• Mites may be more widespread on a baby's skin, causing pimples over the trunk, or small blisters over the palms and soles. • In young children, the head, neck, shoulders, palms, and soles are involved. • In older children and adults, the hands, wrists, genitals, and abdomen are involved.

Epidemiology

• Scabies infestation occurs worldwide and is very common. • It has been estimated that worldwide, about 300 million cases occur each year. Human scabies has been reported for over 2,500 years. • In the U.S., it is seen frequently in the homeless population but occurs episodically in other populations of all socioeconomic groups as well. Pathophysiology

• Direct skin-to-skin contact is the mode of transmission. • Scabies mites are very sensitive to their environment. They can only live off of a host body for 24-36 hours under most conditions. • Transmission of the mites involves close person-to-person contact of the skin-to-skin variety.

• The mites that cause scabies, burrow into the skin and deposit their eggs, forming a burrow that looks like a pencil mark. • Eggs mature in 21 days. • The itchy rash is an allergic response to the mite.

Signs and tests

• Examination of the skin shows signs of scabies. • Tests include an examination under the microscope of skin scrapings taken from a burrow to look for the mites. • A skin biopsy can also be done.

Treatment

• Medicated creams are commonly used to treat scabies infections. • The most commonly used cream is permethrin 5%. • Other creams/ointments include benzyl benzoate(25%), sulfur in petrolatum(10%), and crotamiton(10%).

• Lindane (1%) is rarely used because of its side effects. • For difficult cases, some health care providers may also prescribe medication taken by mouth to kill the scabies mites. Ivermectin (10-15mg) is a pill that may be used. • Doctor may also recommend an oral antihistamine to relieve the allergic symptoms.

Duration of Treatment

• With proper treatment, the rash and intense itching of scabies usually begin to subside within one to two days, although some milder itching can persist for a few weeks. Prevention

• Wash underwear, towels, and sleepwear in hot water. • Vacuum the carpets and upholstered furniture. • Itching may continue for 2 weeks or more after treatment begins, but it will disappear if you follow your health care provider's treatment plan. • Patient can reduce itching with cool soaks and calamine lotion.

Complications

• Intense scratching can cause a secondary skin infection, such as impetigo.

• Direct skin-to-skin contact is the mode of transmission.

• A severe and relentless itch is the predominant symptom of scabies.

• Sexual contact is the most common form of transmission among sexually active young people, and scabies has been considered by many to be a sexually transmitted disease (STD).

• Scabies produces a skin rash composed of small red bumps and blisters and affects specific areas of the body.

Impetigo Causes • Impetigo is a contagious, superficial infection of the skin caused by staphylococcus and streptococcus bacteria. • According to the American Academy of Family Physician, both bullous and nonbullous are primarily caused by Staphylococcus aureus, with Streptococcus also commonly being involved in the nonbullous form. • Methicillin-resistant S aureus (MRSA) is becoming a common cause. Symptoms • A single or possibly many blisters filled with pus; easy to pop and -- when broken -- leave a reddish raw-looking base (in infants). • Itching blister: – Filled with yellow or honey-colored fluid. – Oozing and crusting over.

• Rash - may begin as a single spot, but if person scratches, it may spread to other areas. • Skin lesions on the face, lips, arms, or legs, that spread to other areas. • Swollen lymph nodes near the infection (lymphadenopathy).

Epidemiology

• The incidence of impetigo is higher in summer months due to environmental factors such as increased humidity. • Impetigo is the most common bacterial skin infection in children worldwide. • The annual incidence of impetigo in the UK is approximately 80/100,000 in children aged 0 to 4 years, decreasing to approximately 50/100,000 in those aged 5 to 14 years.

Diagnosis

• Diagnosis is based mainly on the appearance of the skin lesion. Infections such as tinea ("ringworm") or scabies (mites) may be confused with impetigo. • A culture of the skin or lesion usually grows the bacteria streptococcus or staphylococcus. • The culture can help determine if MRSA is the cause, because specific antibiotics are used to treat this infection Kinds of Impetigo

• Non-bullous impetigo • Bullous impetigo Non-bullous impetigo

• This form initially presents as small red papules similar to insect bites. • These lesions rapidly evolve to small blisters and then to pustules that finally scab over with a characteristic honey-colored crust. • This entire process takes about one week. • These lesions often start around the nose and on the face, but less frequently they may also affect the arms and legs. • There may be swollen but non-tender lymph nodes (glands) nearby.

Bullous impetigo

• This form of impetigo is caused only by Staph bacteria. • These bacteria produce a toxin that reduces cell-to-cell stickiness (adhesion) causing separation between the top skin layer (epidermis) and the lower layer (dermis).

• This leads to the formation of a blister. (The medical term for blister is bulla.) • Bullae can appear in various skin areas, especially the buttocks and trunk. These blisters are fragile and contain a clear yellow- colored fluid.

Treatment

• Impetigo is not serious and is easy to treat. • Mild cases can be handled by gentle cleansing, removing crusts and applying the prescription- strength antibiotic ointment mupirocin (Bactroban).

• Nonprescription topical antibiotic ointments (such as Neosporin) generally are not effective. More severe or widespread cases, especially of bullous impetigo, may require oral antibiotic medication.

• In recent years, more Staph germs have developed resistance to standard antibiotics. • Bacterial culture tests can help guide the use of proper oral therapy if needed. Antibiotics which can be helpful include penicillin derivatives (such as Augmentin) and cephalosporins such as cephalexin.

• If clinical suspicion supported by culture results show other bacteria, such as drug- resistant Staph (methicillin- resistant Staphylococcus aureusor MRSA), other antibiotics such as clindamycin or trimethoprim-sulfamethoxazole (Bactrim or Septra) may be necessary.

Prevention

• Routine hand washing with soap and warm water is an important and effective mechanism to prevent the spread of impetigo. • Good hygiene practices can help prevent impetigo from spreading. • Those who are infected should use soap and water to clean their skin and take baths or showers regularly.

• It is also a good idea for everyone to keep their fingernails cut short to make hand washing more effective. • If necessary, paper towels can be used in place of cloth towels for hand drying. • Impetigo is contagious, so avoid touching the draining (oozing) lesions.

Complications

• One potentially serious but rare complication of impetigo caused by Strep bacteria is glomerulonephritis (rare). • Many patches of impetigo. • Permanent skin damage and scarring. • Spread of the infection to other parts of the body. • Ecthyma is a more serious form of impetigo.