Fifth disease - 第五病
16个月大第五病 (Fifth disease) ― 两颊变红，像被打了一巴掌，身上出现斑丘疹。
两颊有红斑。
References
Fifth disease ，也称为传染性红斑，是由人类细小病毒 B19 引起的病毒感染。它在儿童中更为普遍，通常影响 4 至 14 岁的儿童。症状通常以轻度发烧、头痛、喉咙痛和流感样感觉开始。孩子们的脸上可能会出现类似 slapped cheeks 的明显红色皮疹，身体、手臂和腿部也会出现图案化的皮疹。在成人中，关节疼痛是一种常见的症状，可能在初次感染几周后出现。值得注意的是，大约 20% 至 30% 的感染细小病毒 B19 的成年人可能不会表现出任何症状。
Fifth disease (erythema infectiosum) is a viral infection caused by human parvovirus B19. It is more common in children than adults and usually affects children ages 4 to 14. The disease often starts with mild fever, headache, sore throat, and other flu-like symptoms. Children can also develop a bright red rash on the face that looks like “slapped cheeks”, along with a lacy or bumpy rash on the body, arms, and legs. In adults, joint aches are a common symptom. Rash and joint symptoms may develop several weeks after infection. About 20 to 30% of adults who are infected with parvovirus B19 will not have symptoms.
Fifth disease (erythema infectiosum) is a viral infection caused by human parvovirus B19. It is more common in children than adults and usually affects children ages 4 to 14. The disease often starts with mild fever, headache, sore throat, and other flu-like symptoms. Children can also develop a bright red rash on the face that looks like “slapped cheeks”, along with a lacy or bumpy rash on the body, arms, and legs. In adults, joint aches are a common symptom. Rash and joint symptoms may develop several weeks after infection. About 20 to 30% of adults who are infected with parvovirus B19 will not have symptoms.
Parvovirus B19 由母亲传染给婴儿的风险约为 33%，大约 3% 的受感染妇女的婴儿会出现并发症。当母亲在怀孕 20 周之前受到感染时，出现血液问题和婴儿体内积液等并发症的机会就会增加。为了开始治疗这种疾病，我们应该通过检测某些抗体（IgM）来检查患者是否曾经接触过细小病毒。如果测试显示过去没有接触过但表明最近感染过，则患者需要在怀孕期间进行密切监测，包括定期进行超声波扫描以检查某些婴儿健康问题。
The rate of vertical transmission during maternal parvovirus B19 infection is estimated at 33%, with fetal complications occurring in 3% of infected women. Fetal complications comprising hemolysis, anemia, and nonimmune hydrops fetalis and fetal loss are more frequent when maternal infection occurs before 20 weeks of gestation. The first step in the management of this patient would be to obtain immunoglobulin (Ig) M and IgG titres against parvovirus to evaluate if the patient has had previous immunity against the disease. If results are negative for IgG but positive for IgM (ie, primary infection), this patient would need close obstetrical monitoring for the following weeks, including serial ultrasounds to rule out fetal anemia and hydrops fetalis.
The rate of vertical transmission during maternal parvovirus B19 infection is estimated at 33%, with fetal complications occurring in 3% of infected women. Fetal complications comprising hemolysis, anemia, and nonimmune hydrops fetalis and fetal loss are more frequent when maternal infection occurs before 20 weeks of gestation. The first step in the management of this patient would be to obtain immunoglobulin (Ig) M and IgG titres against parvovirus to evaluate if the patient has had previous immunity against the disease. If results are negative for IgG but positive for IgM (ie, primary infection), this patient would need close obstetrical monitoring for the following weeks, including serial ultrasounds to rule out fetal anemia and hydrops fetalis.
第五病 (fifth disease) 以低烧、头痛、皮疹和类似感冒的症状（例如流鼻涕或鼻塞）开始。这些症状过去了，几天后，皮疹出现。鲜红色皮疹最常出现在面部，尤其是脸颊。 （因此得名“拍打脸颊病”）。除了脸颊发红之外，儿童还经常在身体的其他部位出现红色、花边状的皮疹，其中上臂、躯干和腿部是最常见的部位。
这种疾病通常较轻，但在孕妇中，妊娠前三个月的感染与胎儿水肿有关，导致自然流产。
○ 治疗
不需要特殊治疗，因为它通常会随着时间的推移而改善。