Smallpox (smallpox, variola) is a highly virulent epidemic disease caused by the smallpox virus, with a high mortality rate. However, through the promotion of cowpox vaccination and years of global surveillance, the World Health Organization officially declared in 1980 that smallpox had been eradicated worldwide. However, attention must be paid to its potential re-emergence.

bubble_chart Epidemiology

Smallpox is highly contagious and remains infectious from the onset of fever until the scabs fall off. People of all ages are susceptible. Once infected, a person gains lifelong immunity.

bubble_chart Clinical Manifestations

The incubation period is generally 12 days. The onset is sudden, with body temperature rapidly rising to 39-40°C, accompanied by symptoms such as dysphoria, headache, sore throat, limb soreness, shivering, vomiting, and loose stools. The patient remains conscious, with occasional delirium, convulsions, and signs of exhaustion. The rash fully develops over 2-4 days. The rash is centrifugally distributed, more prevalent on the head, face, and proximal limbs, and less on the trunk. Initially, it appears as small dark red plaques, which develop into papules within a few hours. After 2-3 days in the papule stage, they gradually turn into vesicles, forming pox blisters surrounded by a red halo. By days 5-8, the vesicles fill with pus, becoming pustules that are painful, with a deepening red halo. At this stage, the temperature rises again, known as "suppurative fever." By days 10-14, the body temperature gradually decreases, the pustules dry and shrink, or rupture and scab over, eventually forming scab caps. Transmission from one meridian to the next takes 2-4 weeks, after which the scab caps naturally fall off, causing itching and leaving behind pockmarks, known as "pockmarks."

Before the eruption, the symptoms are similar to those of other pestilences such as influenza, encephalitis, meningitis, cold-damage disease, toxic scarlet fever, etc., and can only be distinguished based on epidemic reports, otherwise difficult to differentiate. After the eruption, diagnosis can be made based on the following three points.

1. If the individual has been vaccinated against smallpox (as evidenced by a scar) and is under the age of 3 to 5 years, it is unlikely to be smallpox.

2. During a physical examination, carefully inspect the distribution of the rash across the body. The rash of smallpox is centrifugal in distribution, whereas that of chickenpox is centripetal, which can help differentiate mild smallpox from severe chickenpox.

3. If the smallpox vaccine is successfully administered three days after the eruption, it can be concluded that the rash is not smallpox, as the smallpox vaccine can only be effective if administered during the incubation period of the disease.

bubble_chart Treatment Measures

1. General Care Smallpox patients must be isolated until all scabs have fallen off and ulcers have healed. Maintain fresh indoor air with appropriate humidity and temperature, frequently change positions to prevent bedsores. Ensure adequate fluid supply, sufficient protein and vitamins in the diet, and pay attention to oral hygiene.

2. Symptomatic Treatment For patients with high fever or dysphoria, administer antipyretics and sedatives. Actively treat local corneal membrane ulcers. In cases of secondary bacterial infection or sepsis, add antibiotics and systemic supportive therapy.

3. Local Treatment The principle is to keep the local area clean and tidy. Reduce pain and itching, prevent scratching, and avoid secondary infections.