EMedicineHealth categorizes rosacea and psoriasis as non-itchy rashes. Psoriasis rashes commonly manifest on the knees, elbows and neck as patches of thickened dry skin. Rosacea appears on the face, as a large flushed area, and it can be accompanied by pink acne-like bumps. A small number of patients with infectious mononucleosis can develop a non-itchy rash as well.
Subacute lupus erythematosus causes a non-itchy dry rash to appear on the upper back and chest. This rash typically occurs after sun exposure; it appears as lumps, purple spots, scaly lumps or a ring-shaped rash.
DermNet New Zealand lists discoid eczema as an additional cause of a non-itchy rash. Discoid eczema develops as skin lesions that either blister and ooze or remain dry. It appears most commonly on the lower legs. It is triggered by the occurrence of a cut, insect bite, thermal burn or surgical wound, according to DermNet New Zealand. Aggressive forms of discoid eczema spread to the arms and torso.
Folliculitis affects the hair follicles, often as an aggravated reaction to hair removal techniques, such as shaving or waxing. Angiodema can be caused by an allergic reaction to foods, drugs or insect venoms, notes DermNet New Zealand. Rashes associated with angiodema can be itchy or non-itchy.