Erythema Infectiosum, also known as the fifth disease, is a benign infectious disease possibly caused by a virus.

bubble_chart Etiology

Since this disease often occurs collectively in children, some scholars believe it to be a viral pestilence, but no virus has been isolated. It may also be a type of enterovirus.

bubble_chart Clinical Manifestations

The incubation period is 5 to 14 days. Most patients are children aged 4 to 12. The rash often appears suddenly without systemic symptoms, with only a few patients experiencing mild fever, and occasionally sore throat, vomiting, conjunctival and pharyngeal congestion. The rash first appears on the cheeks as edematous butterfly-shaped erythema with clear borders, no scales, increased local temperature, and occasionally mild itching and burning sensation. The rash does not occur around the lips. After 1 to 2 days, symmetrical, well-defined lace-like or reticular papules appear on the trunk, buttocks, and limbs, which are characteristic of the disease. After 4 to 5 days, the erythema fades from the cheeks and upper trunk. The order of rash disappearance is the same as the order of eruption. After the rash subsides, there is no desquamation. Sometimes it recurs. It is common in spring, and the course of the disease is about 10 days. The prognosis is good.

bubble_chart Auxiliary Examination

1. Blood Routine - White blood cells are normal or slightly decreased, with an increase in lymphocytes and eosinophils.

2. Histopathology - Epidermal cell edema, dilation of blood vessels in the dermal papillary layer, endothelial swelling, and chronic inflammatory cell infiltration around blood vessels, hair follicles, and sweat glands.

Based on the presence of a butterfly-shaped, edematous, well-defined erythema on the face, with mild systemic symptoms and common occurrence in children during spring, a diagnosis can be made.

bubble_chart Treatment Measures

During the illness, isolation is required until the rash subsides. Generally, symptomatic treatment is sufficient, and no special intervention is needed.

bubble_chart Differentiation

(1) Scarlet Fever This disease presents as an acute sexually transmitted disease, with clinical manifestations including sore throat, high fever, a diffuse erythematous rash, a pale circle around the mouth, strawberry tongue, and post-recovery peeling. Pastia's sign: positive.

(2) Rubella Upper respiratory catarrhal symptoms are more pronounced, fever, measles-like rash, and swelling of the lymph nodes behind the ears and at the back of the neck.

(3) Measles High fever, pronounced upper respiratory catarrhal symptoms, a rash characterized by maculopapular eruptions with normal skin between the lesions. Early in the course, Koplik's spots may be seen on the buccal mucosa.