What's your question? Ask

This may be winter burn from the very cold winter suffered across the United States this past winter.
Here is a couple of articles with more information.

https://www.gardeningknowhow.com/plant-problems/environmental/winter-burn-in-evergreens.htm

https://www.gardeningknowhow.com/ornamental/shrubs/juniper/growing-creeping-junipers.htm

Well cared for Juniper Trees can live 20 years.

Your trees may be nearing the end of their lifespan.

Here is a link with more information.

https://www.gardeningknowhow.com/ornamental/shrubs/juniper/growing-juniper-trees.htm

This article may help: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/reversing-soil-salinity.htm

If the pH is at 7, it is considered neutral, but anything over this is considered alkaline. Here is more information: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/alkaline-soil-plants.htm

This can be a fungus. Cut the brown area away from the plant and even remove the mulch that was around the plant.
Dispose of this material.
Treat the Juniper with Neem Oil.

https://www.gardeningknowhow.com/ornamental/shrubs/juniper/growing-creeping-junipers.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm

This is likely a fungus issue.
Follow the care and treatment as indicated.

Here is a link with more information.

http://www.clemson.edu/extension/hgic/pests/plant_pests/shrubs/hgic2056.html
https://www.gardeningknowhow.com/ornamental/shrubs/juniper/care-of-junipers.htm

I cannot speak to your reaction to the sap, but recommend covering arms and legs with longer clothing and wearing gloves when trimming plants or pruning.