Is There Such A Thing As a Beneficial Sunburn?

  Yes it's called Minimal Erythemal Dose ( MED) when using a Wound Lamp for healing bed sores, decubitus ulcers, pressure sores.

  Minimum Erythemal dose is the amount of ultraviolet light that will cause a barely perceptible redness of the skin within 24 hours of exposure.  This amount of dosage was the amount of ultraviolet - c ( UVC) range energy necessary to