Drug-induced rash is the most commonly reported drug reaction and occurs in a dizzying array of presentations. Changes in lean and fat body tissue, gastrointestinal acid and mucosal permeability, cardiac output, and renal and hepatic metabolism can affect drug absorption, distribution, metabolism, and elimination. Elders may develop cutaneous eruptions from drugs or biologics and be more sensitive to topical medications. Almost all medications have been associated with rash to some degree. Consultant pharmacists should be able to distinguish between the rashes that are uncomfortable from those that are potentially life-threatening. Some drug therapies tend to induce or aggravate "companion" rashes. With select medications, rash is a clinical indicator that the medication is working. Extensive or unusually painful drug-induced skin conditions are rare, but often require fast action by health care providers to direct the patient to life-saving help. Many of these rashes are associated with high mortality, severe complications, and potential chronic disability. Awareness of the drugs that are most likely to cause a rash can help consultant pharmacists work with the clinical team to arrange appropriate care.