Pediatric emergency medicine trisk 458

Kawasaki Disease (see Chapter 101 Rheumatologic Emergencies ) Kawasaki disease can present with a wide variety of rashes, including morbilliform and urticarial Conjunctivitis, when present, is unique in that it is nonexudative with limbal sparing Other dermatologic manifestations include red cracked lips, strawberry tongue, and erythematous oropharynx, and erythema, swelling, and/or induration of peripheral extremities The most commonly associated rash is a generalized exanthem with raised erythematous plaques; however, the rash may also present with an erythematous maculopapular, morbilliform, scarlatiniform, or erythema marginatum–like pattern Peeling in the diaper/groin area is also frequently observed early The exanthem may be fleeting or persist for to days During the later stages of the acute phase, periungual desquamation and peeling of the palms, soles, or perineal area develop Measles (Rubeola) Measles was one of the most common viral exanthems before the measles vaccine It is now on the rise again because of increased opting out of vaccinations for children The incubation period is 10 to 14 days after direct contact with droplets from an infected person In its classic form, measles has a highly characteristic natural history Two to days after the onset of the prodromal symptoms of cough, coryza, conjunctivitis, and fever, Koplik spots occur in the mouth, followed 12 to 24 hours later by the cutaneous exanthem Most typically, Koplik spots appear as pinpoint white lesions on a red base on the buccal mucosa adjacent to the molars; however, they may be seen on any of the mucosal surfaces of the oral cavity except the tongue The measles exanthem begins on the head as reddish maculopapules and spreads caudally during the next to days Within to days of its appearance, the discrete maculopapular lesions coalesce to produce the confluent phase of the rash Hence, within to days of onset, the rash on the face becomes confluent, whereas the rash on the lower extremities still consists of individual maculopapules Modified measles occurs in children who have received serum immunoglobulin after exposure to measles Measles may still occur, but the incubation period may be delayed up to 21 days The symptoms, although following the usual progression, will be milder A faint rash and mild febrile illness may occur to 10 days after immunization with the live attenuated measles vaccine Rocky Mountain Spotted Fever RMSF is caused by Rickettsia rickettsii transmitted by the bite of a tick (see Chapter 66 Rash: Bacterial and Fungal Infections/Rash: Maculopapular ) Although initially confined to the Rocky Mountain States (hence, its name), confirmed cases have been reported from all parts of the United States with varying tick vectors The primary determinants in patient outcome are early diagnosis and treatment The best outcomes are associated with the initiation of doxycycline therapy by day five of illness The rash of RMSF begins on the third or fourth day of a febrile illness as a morbilliform eruption on the extremities, most commonly the wrists and ankles Over the next days, the rash becomes generalized by spreading centrally to involve the back, chest, and abdomen Initially, the rash consists of erythematous macules that blanch on pressure; they then become more confluent and purpuric Notably, the hemorrhagic lesions predominate in the peripheral distribution, involving the palms of the hands and the soles of the feet The severity of the rash is proportional to the severity of the disease All patients with RMSF have some degree of vasculitis that is the basis for many of the associated systemic symptoms An overall toxic appearance is common Systemic signs and symptoms include fever, headache, myalgia, conjunctivitis, vomiting, seizures, myocarditis, heart failure, shock; periorbital, facial, or peripheral edema; and disseminated intravascular coagulation or purpura fulminans Diagnosis is best made by polymerase chain reaction (PCR) testing Thrombocytopenia, hyponatremia, and increased aminotransferases usually develop as the disease process progresses Doxycycline is the drug of choice for therapy in patients of all ages at a dose of mg/kg/day in two divided doses (maximum of 100 mg two times a day), intravenously or orally Ehrlichiosis Ehrlichiosis is most common during the warmer months when ticks are most prevalent Nomenclature has undergone multiple changes Currently, disease in the United States is due to three distinct obligate intracellular bacteria: Ehrlichia chaffeensis (human monocytic ehrlichiosis or HME), Anaplasma phagocytophilum agent (human granulocytic anaplasmosis or HGA), or Ehrlichia ewingii (E ewingii ehrlichiosis) Infections with any of these bacteria cause an illness very similar to RMSF Rash is a less consistent feature of ehrlichiosis but when present may be macular, morbilliform, or petechial and is more commonly seen in pediatric patients infected with E chaffeensis Unlike RMSF, rash may occur anywhere on the body and is less commonly seen on the palms and/or soles Vasculitis is less prominent, and leukopenia, anemia, and hepatitis are more common in ehrlichiosis than in RMSF As for RMSF, doxycycline is the drug of choice for therapy in patients of all ages and at the same dose of mg/kg/day in divided doses (maximum 100 mg twice a day) Therapy is continued until the patient is afebrile for at least to days and for a minimum total course of to 10 days Clinical improvement is usually apparent within days, and if not, an alternative diagnosis should be sought Disease may be more severe or even fatal in untreated patients Early initiation of therapy minimizes morbidity and mortality Dengue Fever Dengue fever is caused by four dengue viruses transmitted by Aedes mosquitos and is seen in tropical and subtropical areas of almost all continents (including areas of Puerto Rico and the Caribbean basin and now in Florida) Many cases are asymptomatic In symptomatic cases, initial constitutional symptoms include sudden onset of high fever, severe headache, myalgia, arthralgia, and abdominal pain During the course of fever that lasts to days, back and leg pain may be severe, hence, the disease’s nickname “break bone fever.” The development of a hemorrhagic vasculitis, most common in patients younger than 15 years, leads to the more concerning subtype called dengue hemorrhagic fever The term dengue shock syndrome is used in even more severe cases when increased vascular permeability leads to shock Encephalopathy, hepatitis, myocardiopathy, intestinal bleeding, and pneumonia are other complications Two distinct rashes may be seen, which coincide with the disease’s biphasic fever pattern The first rash is a generalized, transient, macular rash that blanches under pressure and is seen within the first 24 to 48 hours of the onset of systemic symptoms The second rash coincides with or occurs to days after defervescence and is generalized morbilliform, sparing the palms and soles Diagnosis is based on clinical suspicion and potential exposure based on the virus’s geographic distribution Serologic testing is available as is viral isolation and measurement of serum immunoglobulin antibodies in paired serum specimens obtained weeks apart Treatment is supportive, and may require aggressive fluid management and pain control Intravenous immunoglobulin and/or plasma exchange may be of benefit in severe cases Causes of Other Widespread Rashes Associated With Fever Non–life-threatening illnesses associated with fever and widespread rash include coxsackievirus infections, erythema infectiosum, scarlet fever, and early varicella Harder to diagnose are rashes associated with Epstein–Barr virus, Mycoplasma infections, roseola infantum, disseminated gonorrhea, and secondary syphilis Erythema Infectiosum (Fifth Disease) Erythema infectiosum is a benign disease caused by parvovirus B19, the same virus that can cause aplastic crises in patients with sickle cell anemia For the immunocompetent, nongravid host, fifth disease is usually of no consequence, with the only systemic symptom being fever in 15% to 30% of cases On the face is a characteristic, intensely erythematous, “slapped cheek” rash, often with relative circumoral pallor ( Fig 88.15A ) In addition, a symmetric red lace-like rash is seen on the arms and then trunk, buttocks, and thighs, which may be pruritic ( Fig 88.15B ) In its acute phase, the rash usually lasts only for a few days but can wax and wane in intensity with environmental changes (e.g., exposure to heat or sunlight) for weeks and sometimes months In a small subset of patients, parvovirus B19 causes the atypical papular purpuric gloves and socks syndrome (PPGSS) with a typically painful purpuric exanthem limited to the hands and feet Immunocompromised children or those with hemolytic anemias can develop red cell aplasia and symptoms associated with a chronic anemia Diagnosis is usually made on a clinical basis alone but may be confirmed in an immunocompetent host by measuring parvovirus B19–specific IgM antibody PCR is the best modality for diagnosis in an immunocompromised host No specific therapy is necessary in immunocompetent hosts For a chronic infection in an immunodeficient patient, IVIG therapy should be considered Because parvovirus is associated with fetal anemia, congestive heart failure, and hydrops, exposed pregnant women should be referred to their physicians to discuss possible parvovirus antibody testing Scarlet Fever Scarlet fever is caused by phage-infected Group A Streptococcus that makes an erythrogenic toxin This disease does not appear to be any more serious than Group A streptococcal infection without rash Scarlet fever is most commonly associated with streptococcal pharyngitis but may occur in association with pyoderma or an infected wound The diagnosis of scarlet fever can be made clinically in a child with signs and symptoms of pharyngitis who has a fine, raised, generalized morbilliform rash The skin has a coarse or sandpapery feel on palpation Typically, there is sparing of the circumoral area, leading to circumoral pallor There is usually a bright erythema of the tongue and hypertrophy of the papillae, leading to the term ... ehrlichiosis but when present may be macular, morbilliform, or petechial and is more commonly seen in pediatric patients infected with E chaffeensis Unlike RMSF, rash may occur anywhere on the body