AIP, HCP, VP, & ADP

Clinical Features of AIP

Signs and symptoms of AIP usually occur intermittently and include abdominal pain, constipation, muscle weakness, pains in the arms and legs, insomnia, emotional difficulties, rapid pulse, and high blood pressure. Muscle weakness can be severe during a prolonged attack due to the effects of porphyria on nerves that control muscle. In fact, all symptoms of AIP appear to be due to effects on peripheral nerves, the nerves in the abdomen or the central nervous system. Precisely how porphyria produces pain and other symptoms related to the nervous system is not yet well understood. PBG is produced in excessive amounts by the liver in AIP, but it has not been proven that excess PBG can damage nerve tissue.

Because porphyria is rare and its symptoms often suggest other diseases, the correct diagnosis is often delayed. Attacks due to harmful drugs commonly occur before AIP is recognized. Symptoms of porphyria can develop in some people but not in others who inherit AIP. If they occur, symptoms are characteristically intermittent. Some reasons for this variability are as follows:

1. Certain drugs are harmful to porphyria patients. This is likely to occur if drugs are given for other illnesses or at a time when surgery is needed.

2. Hormones are clearly important in activating porphyria. Quite a number of facts suggest this relationship. Porphyria patients metabolize (or break down) hormones differently than do normal subjects, and these hormone break-down products can cause the liver to make more PBG and porphyrins. In children who inherit AIP (detected by the PBG-D test), the condition is latent before puberty. After puberty, AIP may become active in some of these children.
   
   Attacks are more common in women who inherit AIP than in men. Attacks in women often occur during the second half of each menstrual cycle, suggesting that female hormones are more significant than male hormones in bringing AIP from the latent to the active state. Attacks can be produced by oral birth control pills that contain synthetic types of female hormones.
   
   Some women with AIP, on the other hand, have fewer attacks of porphyria after certain types of birth control pills are started. This is thought to be due to a reduction in the rate of formation of their own female sex hormones, as a result of their taking the synthetic hormones in birth control pills. Thus, such synthetic hormones may, at times, be helpful. Some women have benefited from using a low dose estrogen patch.

3. Nutrition is another important factor that can alter the course of an AIP patient. Fasting, a marked restriction of calories or a low carbohydrate diet can cause an attack. A high intake of carbohydrate is beneficial to shorten an attack when it occurs. Most AIP patients do well between attacks on a normal diet. A person with AIP who wishes to lose weight should do so gradually. For more detailed information, you may order the Diet and Nutrition brochure from the APF.

4. Environmental factors such as chemicals of various types, may play a part in predisposing a patient to increased symptoms of AIP. Some studies suggest that the chemicals that are found in cigarettes, insecticides and weed killers have this potential.

5. Alcoholic beverages should be avoided.

6. Other factors may precipitate or exacerbate an AIP attack such as stress of illnesses unrelated to porphyria, extreme emotional stress or physical fatigue