Prurigo nodularis (PN), also known as nodular prurigo, is a skin disease characterised by pruritic (itchy) nodules which usually appear on the arms or legs. Patients often present with multiple excoriated lesions caused by scratching. PN is also known as Hyde prurigo nodularis, Pickers nodules, atypical nodular form of neurodermatitis circumscripta, lichen corneus obtusus. Lichen simplex chronicus is a distinct clinical entity. Signs and symptoms
Nodules are discrete, generally symmetric, hyperpigmented or purpuric, and firm. They are greater than 0.5 cm in both width and depth (as opposed to papules which are less than 0.5 cm). They can appear on any part of the body, but generally begin on the arms and legs. Excoriated lesions are often flat, umbilicated, or have a crusted top. Nodules may appear to begin in the hair follicles. Nodule pattern may be follicular. In true prurigo nodularis, a nodule forms before itching begins. Typically, these nodules are extremely pruritic and are alleviated only by steroids. Causes
The cause of prurigo nodularis is unknown, although other conditions may induce PN. PN has been linked to Beckers nevus, linear IgA disease, an autoimmune condition, liver disease and T cells. Systemic pruritus has been linked to cholestasis, thyroid disease, polycythaemia rubra vera, uraemia, Hodgkins disease, HIV and other immunodeficiency diseases. Internal malignancies, liver failure, kidney failure, and psychiatric illnesses have been considered to induce PN, although more recent research has refuted a psychiatric cause for PN.
Terazosin, sold under the brand name Hytrin among others, is a medication used to treat symptoms of an enlarged prostate and high blood pressure. For high blood pressure, it is a less preferred option. It is taken by mouth.Common side effects include dizziness, headache, tiredness, swelling, nausea, and low blood pressure with standing. Severe side effects may include priapism and low blood pressure. Prostate cancer should be ruled out before starting treatment. It is an alpha-1 blocker and works by relaxing blood vessels and the opening of the bladder.Terazosin was patented in 1975 and came into medical use in 1985. It is available as a generic medication. In 2019, it was the 203rd most commonly prescribed medication in the United States, with more than 2 million prescriptions. Synthesis

Reaction of piperazine with 2-furoyl chloride followed by catalytic hydrogenation of the furan ring leads to 2. This, when heated in the presence of 2-chloro-6,7-dimethoxyquinazolin-4-amine (1) undergoes direct alkylation to terazosin (3). == References ==