What Are the Emerging Viral Infections?
Emerging viral infections indicate a public health risk that has either i) recently appeared or ii) are rising in incidence. The rise in international travel, migration, urbanization, and climate change have all contributed to the transmission of infections through increased human-to-human contact and the geographic expansion of specific viruses. Emerging infectious diseases tend to be zoonotic in origin. Increased habitat loss and human-animal interaction enhance the possibility of more emerging infectious diseases to develop.
What Are the Dermatological Sequelae of Emerging Viral Infections?
These include:
- Chikungunya Fever: It develops due to the chikungunya virus, transmitted by the mosquitoes Aedes aegypti and Aedes albopictus. Chikungunya is prevalent in Southeast Asia, South Asia, and Africa, but outbreaks are becoming more common in Europe and the US. This global spread has been linked to the rise of the subtropical vector A. albopictus, globalization, and a lack of vector management. Approximately 40 % of patients may experience dermatologic signs, which typically appear in the acute phase within two to three days of fever. These may include pigmentary changes on the central face, vesicles, bullae, morbilliform eruption, erythematous macules, desquamation, and papular, purpuric, urticarial, vasculitic, and acrocyanotic lesions. Aphthous ulcers in the mouth or genital area may also be present.
- Dengue Fever: Dengue is a febrile disease caused by the dengue virus. It is spread by the Aedes mosquito. It is estimated that 390 million people contract the virus annually and it has spread to areas that were not previously endemic due to climate change and population migration. The rash starts as flushing erythema in the upper body and progresses to a widespread, faint, and pruritic morbilliform exanthem with islands of sparing. It appears one to two days after the fever. Other possible symptoms include petechiae, nonpalpable purpura, and mucosal bleeding.
- Ebola: It is caused by the Ebola Virus genus that is responsible for the 2014 epidemic in West Africa, which resulted in 29,000 cases and a 40 % case fatality rate. Smaller outbreaks of E. Sudan in Uganda and E. Zaire in the Democratic Republic of the Congo has occurred since 2014. One of the clinical symptoms is febrile syndrome, which may or may not be followed by pinpoint papules and non-specific eruption of macules around the hair roots five to seven days later. The rash usually begins on the arms and legs, progresses centripetally, and becomes erythroderma, sometimes accompanied by desquamation. Internal bleeding can also happen and appear on the surface as hematomas, ecchymoses, purpura, and petechiae.
- Hand, Foot, and Mouth Disease: The most prevalent cause of hand, foot, and mouth disease (HFMD) is Coxsackievirus A16. But Enterovirus A71 (EV-A71), Coxsackievirus A6, and Coxsackievirus A10 have also been linked to an increasing number of outbreaks in recent years. The symptoms of HFMD include erosive stomatitis and vesicular eruptions of the palms and soles. Other areas that may be affected include the dorsal portion of the hands and feet and the buttocks and perineum. There may also be onychomadesis, nail shedding, and delayed acral desquamation. Eczema coxsackium, or superinfected eczematous skin, is a possible presentation of HFMD in children with atopic dermatitis. Atypical HFMD is characterized by a broad exanthem that resembles erythema multiforme or a disseminated herpes virus infection.
- Measles: It is a highly infectious febrile disease caused by the Paramyxoviridae virus and transmitted via respiratory droplets. Global measles incidence has decreased due to vaccination efforts, with average measles incidence falling by 87 % between 2000 and 2016. Measles outbreaks are becoming more frequent in high-resource settings due to lower vaccination uptake, and it remains the primary cause of death for children in low-resource settings. Patients get an extensive morbilliform rash and Koplik spots, which are tiny white specks on a reddish background visible on the inside of the cheeks.
- Mpox: It is also referred to as monkeypox and is caused by Monkeypox virus (MPXV), an Orthopoxvirus genus virus of the Poxviridae family. The initial transmission mode was from animal to human. But more recent epidemics have been caused by human-to-human contact with respiratory droplets, skin lesions, and fomites. Skin lesions typically appear two to four days after constitutional symptoms but can also be the initial or only indication of an illness. The normal morphology begins as an umbilicated papule, develops into a vesicle, pustule, ulcerated plaque, and re-epithelization. Abscesses and mucosal sores can also develop.
- Anthrax: The aerobic, spore-forming Gram-positive rod Bacillus anthracis is the cause of anthrax. Several regions of the world, including the Middle East, West Africa, Central Asia, India, and South America, are endemic to the strain of B. anthracis. Anthrax has reemerged in the US and Europe, both naturally and as a bioterrorism agent. Cutaneous inoculation causes approximately 95 % of anthrax infections. The characteristic presentation of cutaneous anthrax is a painless lesion on the papulovesicular area that ulcerates and forms an eschar with non-pitting edema. There may be a ring of vesicles surrounding the original lesion.
- Zika Virus: The Zika virus belongs to the Flaviviridae family and can be spread vertically from mother to fetus by sexual contact, blood transfusions, and A. aegypti and Aedes albopictus mosquitoes. About 90 % of individuals had a descending pruritic morbilliform or scarlatiniform rash after the febrile period of three to five days. There are also visible palatal petechiae. The course of the disease is often mild and self-limiting.
- Melioidosis: It is caused by Burkholderia pseudomallei, a Gram-negative rod although Southeast Asia and Northern Australia are the endemic regions for the infection. It has spread throughout Africa, Asia, and the Americas, including Brazil and Mexico. According to recent estimates, there are 89,000 deaths and 165,000 cases worldwide each year. Exposure to contaminated soil or water can result in human infection. Risk factors for infection include old age, diabetes, and occupational exposure. Ten to twenty-five percent of patients experience cutaneous symptoms such as cellulitis, ulcers, pustules, or subcutaneous abscesses. A biopsy is usually recommended in cases of melioidosis patients with either acute or chronic isolated cutaneous symptoms.
Conclusion:
It is vital to remember that dermatological symptoms can differ significantly based on the infectious agent and the individual's immune response. Viral infections can show milder or unusual skin findings. However, some viral illnesses have well-established dermatological patterns. These dermatological sequelae are usually managed with supportive care and identifying the underlying viral infection.
