Studies have been completed showing that the Australian freshwater mussel Alathyria condola are highly susceptible to neurotoxin accumulation. This specific shellfish has shown upwards of 80 ug of neurotoxin accumulation for every 100g of the mussel after a 2-3 day of exposure to the cyanobacteria A. circinalis , which is significant enough to cause health risks for humans. Pathophysiology
The toxins responsible for most shellfish poisonings are water insoluble,  heat and acid-stable, and ordinary cooking methods do not eliminate the toxins. The principal toxin responsible for PSP is saxitoxin. Some shellfish can store this toxin for several weeks after a harmful algal bloom passes, but others, such as butter clams, are known to store the toxin for up to two years. Additional toxins are found, such as neosaxitoxin and gonyautoxins I to IV. All of them act primarily on the nervous system. PSP and its associated toxin can cause paralysis in extreme cases by targeting the sodium ion channels. Saxitoxin is able to bind to the receptor site of a cellular membrane near the sodium ion channel, blocking the entrance and not allowing potassium or sodium to pass into the cell. This blockage restricts the transmission of signals between neurons potentially resulting in paralysis.PSP can be fatal in extreme cases, particularly in immunocompromised individuals. Children are more susceptible. PSP affects those who come into contact with the affected shellfish by ingestion.
The term acne cosmetica refers to acne caused by or aggravated by cosmetics. : 240   The mechanism is thought to be chemically induced plugging of the pilosebaceous orifice. This became a significant problem for dermatologists in the 1970s and 1980s, but with the improved formulations produced by cosmetic chemists in the decades since, a diagnosis of acne cosmetica has become relatively rare in dermatological practice. The terms "non-comedogenic" and "non-acne(i)genic" appeared on moisturizers and other cosmetic compounds as manufacturers introduced re-formulations—sometimes associated with claims that the products were "oil-free" or "water-based". Although early work produced lists of comedogenic chemicals in various strengths and vehicles, it became apparent that one could not predict the actual comedogenicity of a product from its contents; rather, the finished product itself needed use-testing.The production of a low-grade folliculitis by some components of cosmetic products has led to misdiagnosis on occasion. People may not attribute skin reactions to their cosmetics at first, but may notice worsening symptoms after using certain face makeup, sunblock or lip products. Reactions are more likely to occur if applied cosmetics are left on and not stripped after wearing them. See also
List of cutaneous conditions

References


== External links ==