Public understanding of allergy pathology is often inaccurate and can create dangerous misunderstandings. The most common is that you must ingest a protein in order to have an anaphylactic reaction. Another is that inhalation or skin contact cannot cause severe reactions.
Both of these are inaccurate, especially, but not only, for people with mast cell disease. People without mast cell disease have severe reactions to IV contrast without having allergy antibodies to the protein (Singh, 2008). Inhalation can cause anaphylaxis. There are even cases of patients who can tolerate ingestion of a food but not inhalation, such as seen in Baker’s asthma, the second highest cause of occupational asthma in the UK (Ramirez, 2009). While ingestion of protein is the most common mechanism for severe allergic reactions, it is certainly not the only one.
Fragrance allergy is a growing problem worldwide. Fragrance is now one of the top five allergens in North American and European countries and can cause skin, eye and respiratory problems (Jansson, 2001). At least 100 chemicals commonly used in fragrances can cause contact allergies when applied to skin, even passively (Johansen, 2003). European Commission’s Scientific Committee on Cosmetic Products and Non-Food Products’ 1999 list of allergenic substances contained 24 chemicals and 2 botanical preparations, all used as scents (European Parliament and Council Directive 2003/15/EC, 2003).
Though the exact mechanism is not clear, perfume is known to cause asthma and other respiratory problems (Elberling J, 2009). A Dutch study found that isoeugenol, a common component of fragrances, can cause increased proliferation of cells in respiratory tract lymph nodes when inhaled (Ezendam J, 2007). However, more research is needed in this area.
A significant portion of the population also reports adverse reactions to scented products in general, even when worn by others. Products like scent lotions, perfumes, soaps and air fresheners are all cited as problematic. A 2009 paper reported on the results of two surveys of over 1000 people. 30.5% of the general population found scented products on other people to be irritating. 19% reported health effects from air fresheners, and 10.9% reported the venting of scented laundry products as causing symptoms. Percentages were higher among asthma patients and those with chemical sensitivity (Caress SM, 2009).
Symptoms reported from exposure to fragrances on others includes: headaches, chest tightness, wheezing, diarrhea, vomiting, mucosal irritation, reduced pulmonary function, asthma, asthmatic exacerbation, rhinitis, irritation of the airway, nose and mouth, and dermatitis (Caress SM, 2009).
Many of you are aware of the recent dispute over whether or not essential oils can be dangerous. They can. Even in the absence of known chemical triggers, the oils themselves can be triggering to many. As an example, clove oil, which has a large eugenol component, has been tied to severe allergic reactions (A.O. Nwaopara, 2008). Oils of citrus fruits are known to liberate histamine and make it more available to cause mast cell symptoms (Novak, 2007). Furthermore, while the reaction profile of each mast cell patient is unique, the hallmark of mast cell disease is anaphylactic reactions to seemingly harmless substances. Mast cell patients are increasingly being viewed as “canaries in the coal mine” for their ability to detect minute quantities of offensive components. While mastocytosis is rare, affecting about 0.3-13/100000 patients, some level of mast cell activation syndrome (MCAS) is thought to affect a much larger percentage of the population, in the neighborhood of 5% (Molderings, 2014).
Fragrances, from essential oil or otherwise, can cause contact allergies, headaches and respiratory symptoms. In mast cell patients, scents can cause severe full body reactions that are potentially life threatening or fatal.