Patients have markedly reduced whole-body cholesterol biosynthesis associated with suppressed hepatic, ileal, and mononuclear leukocyte hydroxymethylglutaryl-coenzyme A reductase (HMG-CoA reductase), the rate-controlling enzyme in the cholesterol biosynthetic pathway. Whether or not the down-regulation is due to accumulated sitosterol is still debatable, but most recent data indicate that secondary effects of unknown regulators other than sitosterol can lead to reduced HMG-CoA reductase activity in the disease. This is coupled with significantly increased low-density lipoprotein (LDL) receptor expression. Diagnosis
Diagnosis is made by measuring serum plant sterol concentrations. Treatment
The disorder is treated by strictly reducing the intake of foods rich in plant sterols (e.g., vegetable oils, olives and avocados). However, dietary therapy is often never fully sufficient to control this disease since plant sterols are constituents of all plant-based foods. Statins have been used, and while these lower cholesterol levels and may ameliorate atherosclerotic disease, plant sterol levels are insufficiently lowered by their use alone. If dietary treatment alone is insufficient, bile acid-binding resins (e.g., cholestyramine, colestipol) could be considered. In October 2002, a new cholesterol absorption inhibitor, ezetimibe, received US Food and Drug Administration (FDA) approval for use in sitosterolemia. This drug is now the standard of care, as it blocks sterol entry and can be used in combination with bile-acid resins. Finally, ileal bypass has been performed in select cases to decrease the levels of plant sterols in the body, though this therapy was undertaken prior to the advent of ezetimibe.
Pruritus vulvae is itchiness of the vulva, which is the counterpart of pruritus scroti, and may have many different causes. : 56   Patch testing may be used to diagnose the cause. Causes
This condition is a symptom of an underlying condition more often than it is a primary condition. Vulva irritation can be caused by any moisture left on the skin. This moisture may be perspiration, urine, vaginal discharge or small amounts of stool. It may be caused by vaginal infections, vulvitis, HPV (human papilloma virus) infection, anal incontinence, Bowens disease, or dietary irritants (caffeine, potatoes, chilli, capsicum, tomatoes, and peanuts). Treatment with antibiotics can lead to a yeast infection and irritation of the vulva. Some diseases increase the possibility of yeast infections, such as diabetes mellitus. Chronic inflammation of the vulva predisposes to the development of premalignant or malignant changes. == References ==