It is probably due to the successive irritation of nerve fibrils in the skin. At times patients who suffer from it will scarcely be persuaded that it is not due to insects. Yielding to the temptation to scratch invariably makes the disease worse. See also Antipruritics – anti-itch drugs Morgellons References External links Hallucinations Symptoms and signs of mental disorders Substance dependence Delusional parasitosis