What does it mean to dream about rash?
A rash often points to irritation breaking out where you cannot hide it, an inner distress shown on the skin, and sometimes to something that has gotten under your skin.
Four ways to read it
Each reading below comes from a named tradition and a cited source, so you can see where it came from and decide what fits your dream.
Freud
Freud would read a rash as the body speaking what the mind has suppressed, an inner irritation breaking out on the surface. It can mark a tension or a wish that the dreamer cannot keep wholly contained.
After Freud, The Interpretation of Dreams (Brill trans., 1913), public domain.Jung
Jung would see a rash as something repressed pushing visibly through the persona, a distress that will not stay buried. It may mark a feeling or conflict that the self can no longer keep beneath the skin.
Jungian concept (our summary).Modern
Continuity ties a rash to waking irritation and stress, since worry can genuinely show on the body and the dream echoes it. Such dreams often follow days when something or someone has truly gotten under one's skin.
Continuity hypothesis (our summary).Mythological
Old belief read sudden eruptions on the skin as the work of a curse, an ill wish, or a guilt that the body could not hide. Across traditions the marked skin was a thing to be cleansed, the outward sign of an inward trouble needing cure.
Rosmerta Publishing editorial synthesis (after Frazer; Brewer).