Fragrances are mixtures of organic molecules, including esters, aldehydes and alcohols present in a plethora of products (de Groot, 2020). Perfumed products appear in our everyday lives such as personal care (parfums, shampoos), air care (candles, environment fresheners), fabric care (detergents), personal wash (bar soaps), home care (dish wash), and the contact occurs in the daily lives of millions of people (Biniecka and Caroli, 2011).

As there are many different types of scents, there are various classifications for fragrances. A commonly used classification is based on olfactory properties of the substance, such as fruits, green, marine, floral, spice, woody, ambery and musky (Kraft et al., 2000; Armanino et al., 2020).

Cosmetic and household products can be constituted by up to 26 fragrance chemicals, where linalool and limonene are used more frequently followed by citronellol, geraniol, hexyl cinnamal, butylphenyl methylpropional, and benzyl salicylate. Cleaning products, for example, contain volatile organic compounds (VOCs) that are composed by fragrances, preservatives, disinfectants (Gerster et al., 2014).

Despite the widespread use of these substances in different products for personal and domestic use, there are reports of various health adverse events including headaches, contact dermatitis, eye burning, rhinitis, asthmatic crisis, breathing difficulties, among others (Caress and Steinemann, 2009). Several studies have found a relationship between health outcomes and fragrance. A study where a nationally representative population in US (n = 1136) was sampled, revealed that 34.7% reported health problems related to fragrances, among them: 16.7% respiratory problems; 13.2% mucosal symptoms; 12.6% migraine headaches; 9.1% skin problems; 7.0% asthma attacks (Steinemann, 2019).

Although fragrances are known to induce allergy, the mechanistic pathways leading to contact dermatitis and respiratory sensitization have not been yet fully clarified.

This review presents the pathways responsible for the immune responses and elimination of xenobiotic products occurring in the skin and respiratory tract related to exposition to different fragrances. Moreover, it will also describe the most used in vitro models to study immunological responses to fragrances.