No.

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What are the common cardiac conditions that need endocarditis prophylaxis?

High-risk category

• Prosthetic cardiac valves, including bioprosthetic and homograft valves
• Previous bacterial endocarditis
• Complex cyanotic congenital heart disease (e.g., single ventricle states, transposition of the great arteries, tetralogy of Fallot)
• Surgically constructed systemic pulmonary shunts or conduits

Moderate-risk category

• Most other congenital cardiac malformations (other than above and below)
• Acquired valvular dysfunction (e.g., rheumatic heart disease)
• Hypertrophic cardiomyopathy
• Mitral valve prolapse with valvular regurgitation and/or thickened leaflets

Those in which endocarditis prophylaxis not recommended routinely:

Negligible-risk category (no greater risk than the general population)

• Isolated secundum atrial septal defect
• Surgical repair of atrial septal defect, ventricular septal defect, or patent ductus arteriosus (without residua beyond 6 months)
• Previous coronary artery bypass graft surgery
• Mitral valve prolapse without valvular regurgitation
• Physiologic, functional, or innocent heart murmurs
• Previous Kawasaki disease without valvular dysfunction
• Previous rheumatic fever without valvular dysfunction
• Cardiac pacemakers (intravascular and epicardial) and implanted defibrillators

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Respiratory tract

• Tonsillectomy and/or adenoidectomy
• Surgical operations that involve respiratory mucosa
• Bronchoscopy with a rigid bronchoscope

Gastrointestinal tract (A)

• Sclerotherapy for esophageal varices
• Esophageal stricture dilation
• Endoscopic retrograde cholangiography with biliary obstruction
• Biliary tract surgery
• Surgical operations that involve intestinal mucosa

Genitourinary tract

• Prostatic surgery
• Cystoscopy
• Urethral dilation

Those in which endocarditis prophylaxis not recommended routinely:

Respiratory tract

• Endotracheal intubation
• Bronchoscopy with a flexible bronchoscope, with or without biopsy (B)
• Tympanostomy tube insertion

Gastrointestinal tract

• Transesophageal echocardiography (B)
• Endoscopy with or without gastrointestinal biopsy (B)

Genitourinary tract

• Vaginal hysterectomy (B)
• Vaginal delivery (B)
• Cesarean section
• In uninfected tissue:

  Urethral catheterization
  Uterine dilatation and curettage
  Therapeutic abortion
  Sterilization procedures
  Insertion or removal of intrauterine devices

Other

• Cardiac catheterization, including balloon angioplasty
• Implanted cardiac pacemakers, implanted defibrillators, and coronary stents
• Incision or biopsy of surgically scrubbed skin
• Circumcision

(A) Prophylaxis is recommended for high-risk patients; it is optional for medium-risk patients.
(B) Prophylaxis is optional for high-risk patients.

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Unable to take oral medications
Ampicillin. Adults: 2.0 g IM or IV; children: 50 mg/kg IM or IV within 30 mins before procedure.

Allergic to penicillin
Clindamycin. Adults: 600 mg; children: 20 mg/kg orally 1 hr before procedure. Cephalexin or cefadroxil. Adults: 2.0 g; children; 50 mg/kg orally 1 hr before procedure. Azithromycin or clarithromycin. Adults: 500 mg; children: 15 mg/kg orally 1 hr before procedure.

Allergic to penicillin and unable to take oral medications Clindamycin or Cefazolin. Adults: 600 mg; children: 20 mg/kg IV within 30 mins before procedure Adults: 1.0 g; children: 25 mg/kg IM or IV within 30 mins before procedure.

IM indicates intramuscularly, and IV, intravenously.

• Total children's dose should not exceed adult dose.
• Cephalosporins should not be used in individuals with immediate-type hypersensitivity reaction (urticaria, angioedema, or anaphylaxis) to penicillins.

The diagnosis is scabies. It is caused by the mite Sarcoptes scabies hominis. Transmission is by prolonged physical, and usually intimate, contact. Usually 10-15 mites would be present in a normal patient. The more parasites on an individual, the greater the likelihood of transmission.

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What are the clinical differential diagnosis?

The differential diagnosis of scabies includes almost any pruritic dermatosis but most commonly atopic dermatitis, insect bites, pyoderma, and papular acrodermatitis of childhood.

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Scabies can be diagnosed by the bedside. When several members of the family group complain of an itching eruption, scabies is a likely diagnosis. The pathognomonic sign of scabies is a burrow which is an intraepidermal tunnel dug by a female mite where it lives off and lays eggs. A burrow is a serpiginous, linear track, a few millimetres long, slightly raised and with a black dot visible at one end. It is most commonly found on the fingers, axilla and umbilicus. Scabetic nodules over penis and scrotum are virtually pathognomonic of scabies in an itching patient. The diagnosis of scabies may also be confirmed by microscopy examination of the needle scrapes from the burrow which may reveal the mites, eggs or fecal pellet.

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Possible complications include secondary bacterial infection, glomerulonephritis secondary to nephritogenic streptococcal infection, exacerbation of atopic eczema, and parasitophobia.

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What is the treatment?

Permethrin is the treatment of choice because it is well-tolerated and safe. A single application to be removed in 8-12 hours is adequate. It can be used in adult and children over two years old. However, it is expensive. 25% benzyl benzoate emulsion (BBE) is the most widely used scabicide in Hong Kong. It is safe, cheap and effective but it is smelly and may cause irritation. Diluted preparation e.g. 6.25% should be used in children. Malathion and 1% gamma benzene hexachloride are effective alternatives. Both are much less stinging than BBE. Gamma benzene hexachloride may cause neurotoxicity and is contraindicated in pregnancy. Pregnant women with scabies can be treated with BBE or malathion. Other treatments used include: crotamiton cream, 10% sulphur in yellow paraffin. Ivermectin is the only orally effective scabicide but it is not available in Hong Kong. Bed-linen and clothing should be changed and then laundered in the usual way. Close contact should also been treated.

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