The absence of secondary causes of severe hypertriglyceridemia (like e.g. diabetes, alcohol, estrogen-, glucocorticoid-, antidepressant- or isotretinoin-therapy, certain antihypertensive agents, and paraproteinemic disorders) increases the possibility of LPL deficiency. In this instance besides LPL also other loss-of-function mutations in genes that regulate catabolism of triglyceride-rich lipoproteins (like e.g. ApoC2, ApoA5, LMF-1, GPIHBP-1 and GPD1) should also be consideredThe diagnosis of familial lipoprotein lipase deficiency is finally confirmed by detection of either homozygous or compound heterozygous pathogenic gene variants in LPL with either low or absent lipoprotein lipase enzyme activity.Lipid measurements
·        Milky, lipemic plasma revealing severe hyperchylomicronemia;·        Severely elevated fasting plasma triglycerides (>2000 mg/dL);LPL enzyme
·        Low or absent LPL activity in post-heparin plasma;·        LPL mass level reduced or absent in post-heparin plasma;Molecular genetic testing
The LPL gene is located on the short (p) arm of chromosome 8 at position 22. More than 220 mutations in the LPL gene have been found to cause familial lipoprotein lipase deficiency so far. Treatment
Treatment of LPLD has two different objectives: immediate prevention of pancreatitis attacks and long-term reduction of cardiovascular disease risk. Treatment is mainly based on medical nutrition therapy to maintain plasma triglyceride concentration below 11,3 mmol/L (1000 mg/dL). Maintenance of triglyceride levels below 22,6 mmol/L (2000 mg/dL) prevents in general from recurrent abdominal pain.
Another proposed theory is of a water-soluble allergen in the epithelial tissues. Water dissolves the allergen, causing it to diffuse into the tissues, causing histamine release from sensitized mast cells. Diagnosis
Diagnosis of aquagenic urticaria begins with a clinical history and water challenge test. The water challenge test consists of application of a 35°C water compress to the upper body for 30 minutes. Water of any temperature can provoke aquagenic urticaria; however, keeping the compress at a similar temperature to that of the human body (37 °C) avoids confusion with cold urticaria or cholinergic urticaria. In addition, a forearm or hand can be immersed in water of varying temperatures to determine whether temperature is a factor in the patients condition. Aquagenic urticaria differs from aquagenic pruritus, in which contact with water evokes intense itching without visible hives or rash.Once known as a separate, rare disease, aquagenic urticaria is now considered a subtype of general urticaria. The first case was reported by Walter B Shelley et al. in 1964. The condition is more common in women than men, and typically presents for the first time during puberty. Genetics may play a part, and the condition may be related to other sensitivities such as lactose intolerance. Prevention
Desensitization does not seem to work for aquagenic urticaria; a patient will continue to react to water no matter how gradually or frequently it is introduced. Topical application of antihistamines like 1% diphenhydramine before water exposure is reported to reduce the hives.