Thông tin tài liệu
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
Ngày đăng: 22/10/2022, 12:45
Xem thêm:
