Br ans 3-10

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					BR Answers for the week of 3-10 Question 246 D The combination of eye pruritus, watery discharge, and nasal congestion reported for the boy in the vignette suggests allergic conjunctivitis. Allergic conjunctivitis is characterized by tearing, conjunctival edema (chemosis), and eyelid edema. Intense pruritus is typical, which helps the clinician distinguish allergic conjunctivitis from infectious causes, which usually do not cause significant itching. Allergic rhinitis is a common association, but other signs of atopy, such as eczema or asthma, may be seen as well. Eye involvement typically is bilateral, and seasonal recurrence may be elicited on history. Oral antihistamines can decrease the symptoms of both the conjunctivitis and rhinitis. Other treatment options include cool compresses and topical cromolyn sodium. Because allergic conjunctivitis is not contagious, isolation is not required. Viral conjunctivitis is characterized by bilateral mucoserous discharge and conjunctival injection. Adenovirus is the most common cause. Bacterial conjunctivitis is associated with mucopurulent eye discharge and conjunctival papillae, and patients may report a foreign body sensation. Bacterial conjunctivitis should be treated with topical antibiotic drops unless otitis media is also present. A foreign body in the eye causes tearing, pain, and conjunctival erythema unilaterally. Fluorescein staining often reveals a corneal abrasion, and irrigation with normal saline can help flush out the foreign body. Question 153 D Leukocoria (Item C153A) is seen as a white pupil when the eye is viewed with an ophthalmoscope, penlight, or in room light. Children who have leukocoria have an abnormal red reflex. A number of different conditions are associated with leukocoria, including neoplastic conditions (eg, retinoblastoma) (Item C153B), retinal abnormalities (eg, retinopathy of prematurity), developmental abnormalities (eg, chorioretinal coloboma), inflammatory conditions (eg, toxocariasis), and other conditions, such as cataracts. Cataracts are a major cause of leukocoria. Approximately 25% of the cases are familial, one third are related to maternal infections, one third are idiopathic sporadic cases, and the remainder are related to particular syndromes and systemic diseases, some of which are hereditary. Maternal infections that cross the placenta, such as toxoplasmosis and rubella, cytomegalovirus (CMV), herpes, human immunodeficiency virus, and varicella infections often cause characteristic eye conditions. Of these, congenital rubella infection is associated most commonly with congenital cataracts. Maternal rubella infection causes congenital rubella in as many as 85% of neonates if it occurs in the first 4 weeks of gestation; the occurrence rate is only 5% if rubella occurs in the third or fourth month of gestation. Common findings in infants who have congenital rubella include eye abnormalities, such as cataracts, congenital glaucoma, and retinopathy, as well as sensorineural hearing loss, heart disease (peripheral branch pulmonary artery stenosis, patent ductus arteriosus), and mental retardation. Affected infants often also have intrauterine growth retardation, hepatosplenomegaly, thrombocytopenia, and purpuric skin lesions (blueberry muffin rash) (Item C153C). Approximately one third of neonates who are born with herpes simplex infections have skin, eye, and mouth disease. Conjunctivitis and keratitis can result from infection, but cataracts are rare. CMV infections (Item C153D) and toxoplasmosis (Item C153E) can cause hearing impairment, but they usually do not cause cataracts. Chorioretinitis is seen more commonly with these infections. Infants born with congenital human immunodeficiency virus infection are at risk for opportunistic infections such as CMV, varicella-zoster virus, and herpes simplex virus. As a result, they can develop CMV chorioretinitis and herpetic ocular lesions.

Question 113 D Tears enter either the upper or lower punctum at the medial aspect of the eye and drain into the nasolacrimal duct (NLD). Among neonates, obstruction of the NLD frequently occurs at the site where the duct passes through the maxilla into the nose. Some 6% of newborns exhibit obstruction (Item C113A) when the embryonic structures fail to fully canalize. NLD is observed with increased frequency in certain populations, including preterm infants and children who have Down syndrome. Signs of obstruction include pooling or overflowing of tears, which may not be observed until normal tear production develops. Often, there is accumulation of mucoid material at the medial canthus. Stasis of tears in the obstructed NLD results in conditions favorable for bacterial infection. Progression of infection can lead to cellulitis of the overlying soft tissue. Preferred management of the infant described in the vignette is to recommend massage overlying the NLD two to three times daily and cleansing of the lids as necessary. When infection complicates the obstruction of the drainage system, instillation of a topical ophthalmic antibiotic is justified, but systemic antibiotics are not indicated. NLD obstruction typically resolves by 9 to 12 months of age. Persistence of symptoms beyond this time justifies referral to an ophthalmologist for possible probing of the NLD. For the patient in the vignette, the cornea is not involved, and fluorescein staining would not be beneficial. Instillation of a topical ophthalmic corticosteroid is not indicated in the management of this disorder and is associated with significant risks. Question 227 D Retinopathy of prematurity (ROP) is the leading neonatal cause of blindness in the United States. Up to 400 infants each year are blinded by this condition. It affects 20% to 50% of all neonatal intensive care unit (NICU) patients weighing less than 1,500 g, with particular predilection for the smallest and most immature newborns. Blindness is greatly increased in infants who have stage 3 or 4 disease. The theories of contributing causal factors include extreme prematurity, very low birthweight, exposure to supplemental environmental oxygen, possible oxidizing agent exposure (including iron), and the generation of inflammatory cytokines. Perturbation of programmed angiogenesis in the developing retina ex utero and corresponding metabolic changes result in certain vascularized and ischemic zones of the retina. Vascular endothelial growth factor is altered, and a proliferative vasculopathy that has immature, leaky, and tortuous tufts of new vessels jeopardizes

perfusion of the retina and imparts biomechanical traction upon it. Results of these processes include impaired peripheral vision in the peripheral zones of vascularity and potential retinal detachment with corresponding blindness or visual field deficits. The greatest risk for ROP is in infants born at less than 29 weeks' gestation who weigh less than 1,200 g. Because retinal vascularity generally is completed by 37 to 44 weeks' gestation, prematurity itself confers risk, but the risk is shifted toward the extreme end of prematurity. Oxygen therapy is a contributing risk factor, but imposes the greatest risk in the smallest and most immature infants. Myopia is more common in very lowbirthweight preterm infants than in term infants, but a family history of myopia has no bearing on the risk of ROP. In view of these facts and findings about ROP, the American Academy of Pediatrics, the American Academy of Ophthalmology, and the American Association for Pediatric Ophthalmology and Strabismus jointly published guidelines for ROP screening examination of preterm infants. Candidates for screening include infants whose birthweights are less than 1,500 g, whose gestational ages are less than 32 weeks, and selected infants weighing 1,500 to 2,000 g at birth who have an unstable clinical course if judged to be at risk by the attending pediatrician or neonatologist. The examination should be performed by a qualified and experienced ophthalmologist, and the results should be reported using the International Classification of Retinopathy of Prematurity. The first examination should be performed between 4 and 6 weeks of postnatal age or at a corresponding postconceptual age of 31 to 34 weeks, whichever is later. Question 128B A red eye in a patient who wears contact lenses may represent dangerous corneal infections due to gramnegative bacteria or fungi or to breakdown and ulceration of corneal epithelium. Such patients should have their contact lenses removed and be evaluated by an ophthalmologist within 12 hours. Empiric antibiotics are not recommended; antibiotic therapy should be directed by the ophthalmologist, depending on the problem identified. For those who do not wear contact lenses and who have either corneal abrasion or bacterial conjunctivitis, empiric therapy with a topical antibiotic is appropriate. Common causes for red eye in contact lens wearers include microbial keratitis, contact lens-induced peripheral ulcer (CLPU), and contact lens-induced acute red eye (CLARE). Microbial keratitis is an infection of the cornea characterized by excavation and necrosis of tissue. Inappropriate treatment or a significant delay in treatment can result in visual impairment. Removal of contact lenses and frequent instillation of sterile saline drops generally result in complete recovery from CLPU and CLARE. Fluorescein stain is taken up by damaged ocular epithelial cells. In a corneal abrasion, fluorescein uptake is focal at the site of injury. With microbial keratitis and CLARE, the uptake is both multifocal and diffuse. Prescribing ophthalmic antihistamine drops and asking the patient to return for re-examination in 2 to 3 days are unnecessary delays to further evaluation and treatment by an ophthalmologist . Question 214 E Since the advent of antibiotics, intracranial complications of otitis media have become increasingly uncommon, but the incidence of infratemporal complications of the middle ear, mastoid air space, and adjacent structures remains unchanged. Hearing loss is the most common complication. Although tympanostomy tubes often are placed for chronic otitis media, whether they prevent hearing loss remains controversial. Other complications of otitis media include perforation of the tympanic membrane, otorrhea, and mastoiditis. Chronic infection may lead to cholesteatoma, and tympanostomy prevents this complication. Ear drainage is common after tympanostomy and myringotomy. Intracranial suppurative complications of otitis media, such as meningitis, lateral sinus thrombosis, epidural and subdural abscess or empyema, and otitic hydrocephalus resembling pseudotumor cerebri, now occur in far less than 1% of children. The affected child may present with fever, irritability, malaise, and signs of increased intracranial pressure, such as headache, vomiting, diplopia, or papilledema. A focal seizure also may occur.

Question 129 C Insertion of small objects such as beads, berries, seeds, and paper into the nares is a common practice of young children. Undetected nasal foreign bodies can lead to local irritation, mucosal edema, and possible infection, producing a bloody, mucous discharge. This sequence of events frequently results in a noticeably unpleasant odor that may be perceived as generalized body odor (bromhidrosis), as described for the boy in the vignette. Allergic rhinitis generally produces thin, watery secretions that occur seasonally or year-round. Bromhidrosis is not present. Epidermolytic hyperkeratosis (EHK), an autosomal dominant disorder, is characterized by extensive skin scaling at birth, erythroderma, and recurrent bullae formation. By school age, bromhidrosis may result, as thick, dirty-yellow scales ((Item C129A) develop on palms, soles, elbows, knees and become malodorous due to bacterial colonization. Purulent nasal secretions are not characteristic of EHK. Pachyonychia congenita is a rare genodermatosis in which combinations of ectodermal defects produce thickened, tented nails(Item C129B); palmoplantar hyperkeratosis; and hyperhidrosis that leads to marked foot odor. Premature adrenarche is an early maturational event of adrenal androgen production in which sexual hair appears before the age of 9 years in boys who have no other evidence of pubertal development. Axillary odor is common.

Question 140 D Antimicrobial therapy is indicated for patients who have dental infections if there is associated cellulitis or facial swelling, as described for the patient in the vignette. Many dentists want to try to treat the infection with antimicrobial agents prior to repairing or removing the involved tooth. Penicillin remains the antibiotic of choice for dental infections. If the patient is allergic to penicillin, clindamycin or erythromycin is an acceptable alternative. Azithromycin, cefdinir, cephalexin, and trimethoprim-sulfamethoxazole are not indicated for dental infections. Dental caries caused by Streptococcus mutans and other streptococci destroy most of the tooth and invade the dental pulp. Pulpitis (inflammation of the pulp) can lead to extension of the infection beyond the tooth to the periapical tissues of the periodontal ligament, possibly resulting in an abscess. Depending on the location of the tooth involved, the patient may develop swelling on the face or below the jaw. Fever, facial swelling, and tooth pain that is exaggerated when the tooth is touched usually indicate an abscess. Abscesses can have a polymicrobial etiology, including anaerobes (eg, Actinobacillus actinomycetemcomitans), especially when periodontal disease also is present. Careful attention to dental hygiene, especially in high-risk patients (eg, those who have complex congenital heart disease) is important to prevent systemic illness. Question 37 C A child who has purulent ear drainage can present a diagnostic challenge. For the child who has no history of tympanostomy tube placement, potential diagnoses include otitis externa, a foreign body in the external meatus with associated irritation, or suppurative otitis media with perforation (Item C37A) . For children who have a history of tympanostomy tube placement, the purulent drainage flows through a patent tube. In all cases, careful history and ear examination are required, although visualization of the tympanic membrane may be difficult or impossible due to the obscuring drainage, as described for the boy in the vignette.

Otitis externa usually is associated with swimming or other water activity in the absence of respiratory symptoms (eg, cough, rhinorrhea) or fever. Physical examination reveals tenderness of the pinna and tragus on manipulation. Otitis media with perforation typically is associated with a history of intense ear pain preceding the appearance of ear drainage, fever, and respiratory symptoms. The initial treatment of otitis externa, otitis media with perforation, and drainage from tympanostomy tubes is the same. Topical treatment with fluoroquinolone drops (eg, ofloxacin, ciprofloxacin) has been found to be as effective as systemic therapy for perforated otitis media. If systemic (oral) therapy is employed, amoxicillin or a suitable alternative may be selected; trimethoprim-sulfamethoxazole is not indicated due to a high prevalence of resistance among causative organisms. There is no evidence of the superiority of combined topical and systemic therapy, and safety of this regimen has not been evaluated completely. Re-examination should be considered for children who do not improve after 3 to 5 days of topical therapy; waiting for completion of a full 10-day course may delay the diagnosis of persistent disease, foreign body, or other complications. Use of neomycin/polymyxin or aminoglycoside (eg, tobramycin) drops may cause ototoxicity and is best avoided. Lavaging the ear is contraindicated if there is a chance that the tympanic membrane is perforated. Otolaryngology referral may be indicated for children who fail to respond to topical therapy, those in whom the inability to see the tympanic membrane persists, or those in whom the perforation does not heal over a period of weeks. Question 85 A Exudative tonsillitis may be viral or bacterial. Important bacterial causes include group A beta-hemolytic Streptococcus (GABHS) (Item C85A) and Staphylococcus aureus (which is usually a superinfection rather than a primary infection). Viral infections represent 70% of exudative pharyngitis in children. Important pathogens include adenovirus, influenza A, Epstein-Barr virus, and herpes simplex viruses. In most settings, the preferred test for diagnosing GABHS pharyngeal infection in a child who has exudative pharyngitis is a rapid streptococcal antigen test. However, because the sensitivity of these tests varies from 70% to 90%, a negative rapid test result should be confirmed by throat culture. Clinical criteria for diagnosing GABHS pharyngitis have been developed. For children who have four of the clinical Centor criteria for GABHS pharyngitis--history of fever, pharyngeal exudates, cervical lymphadenopathy, and absence of cough--90% of cultures for GABHS are positive. Although the boy in the vignette has pharyngeal exudates, he has a cough, rhinorrhea, and low-grade fever, symptoms likely to be associated with a viral upper respiratory tract infection rather than GABHS pharyngitis. In addition, he has no lymphadenopathy, and results of the rapid streptococcal antigen test are negative. Antibiotic treatment of streptococcal pharyngitis reduces the risk of glomerulonephritis and rheumatic fever and remains the standard of care. In developed countries, the risks of antibiotic complications and resistance may outweigh the benefits. Antibiotics also seem to reduce the duration of sore throat by about 16 hours. However, the empiric use of antibiotics for all cases of pharyngitis, even those that include exudates, without confirmatory laboratory testing for streptococcal antigen is not advised and may contribute to increasing antibiotic resistance. The child described in the vignette has conjunctival erythema (Item C85B), which is classic for adenoviral infection. Although Coxsackievirus may cause vesicles on the palate (Item C85C), it generally does not produce conjunctivitis. Sinusitis typically presents with facial pain in the older child or protracted rhinorrhea in the younger child. Infectious mononucleosis may produce an exudative pharyngitis, but typically patients do not manifest cough, conjunctivitis, or vesicles on the palate.


				
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