Complications
Identification of sepsis should be done rapidly using established criteria. Management follows the same principles as for bacterial sepsis and should include: broad-spectrum empirical antibiotic therapy, ideally given within 1 hour of recognition; rapid intravenous fluid resuscitation with assessment of response; vasoactive therapy; appropriate airway management and oxygen administration.[42]
Frequent in severe disease because intravascular fluid tends to be lost through fever, rash, and capillary leak. The accompanying systemic inflammatory response syndrome may cause hypotension as well. This combination of factors reduces renal blood flow and promotes acute kidney injury. Early recognition by monitoring urine output and blood biochemistry will indicate whether intravenous fluids are necessary.
The vesicular skin rash results in a breach of the integrity of the cutaneous barrier to bacterial skin infection, especially when scratched or otherwise traumatised. Antibiotic therapy should be administered. Permanent pitted scarring and discoloration secondary to infection is common.
Patients are at risk of bacterial pneumonia. Pneumonia is a marker of severe disease and is usually associated with mortality. Broad-spectrum antibiotic therapy should be given. Severe pneumonia will cause hypoxia requiring oxygen therapy and possibly mechanical ventilation in an intensive care unit.
Hypotension may be exacerbated by superadded bacterial sepsis and possible viral myocarditis. Hypotension unresponsive to adequate fluid replacement will require treatment with inotropes. If superadded bacterial sepsis is suspected, broad-spectrum antibiotics should be given intravenously. Hypotension secondary to haemorrhage is also possible. This will require blood transfusion and carries a poor prognosis.
Consumption of clotting factors and platelets can occur in severe smallpox, resulting in a bleeding diathesis. This carries a poor prognosis, and should be managed by blood product and platelet infusions as appropriate.
Smallpox may cause a viral encephalitis resulting in a reduced score on the Glasgow Coma Scale and seizures. Treatment is primarily supportive. There may be a role for antiviral agents but there is no supportive evidence. Anticonvulsants should be administered if required.
Inoculation with traditional vaccinia may cause a generalised vesicular rash in the presence of eczema called eczema vaccinatum. A history of vaccination or recent exposure to someone who has been vaccinated on a background of known eczema is key for diagnosis. A polymerase chain reaction of vesicle fluid will be positive for vaccinia DNA but negative for smallpox DNA. Eczema vaccinatum should be distinguished from generalised vaccinia (see below). Tecovirimat is approved in Europe for the treatment of complications following vaccinia vaccination. Other antiviral drugs may also be recommended. Vaccinia immunoglobulin is licensed in the US for the treatment of complications due to vaccinia vaccination.
[Figure caption and citation for the preceding image starts]: Eczema vaccinatum skin lesions on the torso of a smallpox vaccine recipientCDC/Moses Grossman, MD/California Emergency Preparedness Office (Calif/EPO) [Citation ends].
Generalised (disseminated) vaccinia is a self-limiting illness consequent upon vaccinia viraemia occurring in the absence of pre-existing skin disease. Tecovirimat is approved in Europe for the treatment of complications following vaccinia vaccination. Other antiviral drugs may also be recommended. Vaccinia immunoglobulin is licensed in the US for the treatment of complications due to vaccinia vaccination.
Progressive vaccinia starts as a localised but relentlessly progressive spread of vaccinia at the inoculation site and is potentially fatal. It occurs in the markedly immunosuppressed (e.g., congenital immunodeficiencies, cytotoxic chemotherapy, advanced HIV disease). Progressive vaccinia is rare, but fatal if untreated. Tecovirimat is approved in Europe for the treatment of complications following vaccinia vaccination. Other antiviral drugs may also be recommended. Vaccinia immunoglobulin is licensed in the US for the treatment of complications due to vaccinia vaccination.
Pockmarks or pitted lesions (most commonly on the face) occur in the majority of survivors, and they can become infected. Likely due to the destruction of sebaceous glands due to dermis suppuration, excessive scratching, and secondary bacterial infection.[41]
Osteomyelitis and arthritis often pass unnoticed during the acute smallpox illness but lead to long-term osteoarthritis, bone shortening, flail joints, and subluxations.[1]
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