Submitted by grag01 t3_106e1h5 in askscience
Just wondering the perspective of someone smarter than me on this subject. I'm specifically thinking about covid vs herpes virus. Herpes can enter through the skin while covid can't. I'm sure it comes down to the actual characteristics of the physical virus but not sure.
Ps the cold sore virus is a asshole!
iayork t1_j3gt1ku wrote
In general, viruses can’t infect through intact skin. It’s generally believed that infection through skin requires some amount of skin damage, even in the case of herpes simplex I (HSV1, the “cold sore virus”) which is highly adapted to humans and spreads pretty effectively.
On the other hand, it’s probably relatively common to have some amount of skin damage just from normal day-to-day living, so this doesn’t present a complete block to infections.
The details of how HSV gets through skin are still surprisingly unclear, including the amount of damage needed to penetrate.
> The general assumption is that skin lesions can serve as entry portals for HSV-1. Under in vivo conditions, damaged skin can result from various sources ranging from mechanical abrasions or burns to impaired epidermal barriers and dysfunctional immune responses causing eczema herpeticum … Taken together, we hypothesize that successful viral invasion via skin lesions in vivo requires more than mechanically disrupted intercellular junctions.
—Ex Vivo Infection of Human Skin with Herpes Simplex Virus 1 Reveals Mechanical Wounds as Insufficient Entry Portals via the Skin Surface