*Fragrance allergy and skin tolerability to essential oils*

Contact dermatitis (CD) is an inflammatory response of the skin to an irritant
or allergen that has direct skin contact. Reactions to an irritant can cause
irritant contact dermatitis by a non-immunological pathway in which direct
damage is done to epidermal keratinocytes .(1) In contrast, allergic contact
dermatitis (ACD) is an allergen-specific T-cell mediated immune response in
readily sensitized individuals. ACD consists of a type IV hypersensitivity
response to an allergen (also called hapten) that pathologically can be divided
in two phases: the sensitization (induction) phase and the elicitation
(effector) phase. In the sensitization phase the first immunologically relevant
contact with the allergen occurs. In general, this is clinically not visible on
the skin and remains unknown to the patient. But, ACD reactions will occur upon
renewed contact to the specific allergen. This eczematous reaction is the
clinical manifestation of the elicitation phase. (2)
Fragrance allergy occurs approximately in 1-2% of the general population and
is, thus, one of most frequent contact allergens. (3-5) When a patient is
diagnosed with a fragrance allergy, the principal advice is to avoid contact
with all fragrances and potentially cross-reacting or concomitant substances.
(6;7) However in general, sensitization is limited to few fragrance allergens
only. Hence, if a patient would know to which fragrance allergen (s)he is
sensitized to, a specific advise on avoidance and safe alternatives can be
given. Identification of the most frequent sensitizers among fragrances and of
concomitancy between individual fragrances is of important clinical relevance
needed for adequate patient advices.
A group of commercially important fragrances are essential oils. Essential oils
contain various fragrances at different concentrations. (8) There are
indications that fragrance allergens in distinct combinations provoke less
allergic reactions than fragrances tested separately. (9) Since essential oils
contain various fragrances, they might show lower allergenic potentials than
the respective fragrance ingredients tested separately. Moreover, essential
oils contain antioxidants which may also reduce allergenicity.
This study therefore has the aim to improve clinical diagnostics and treatment
of fragrance allergic patients.

REFERENCES

(1) Mark BJ, Slavin RG. Allergic contact dermatitis. Med Clin North Am 2006
Jan;90(1):169-85.
(2) Mark BJ, Slavin RG. Allergic contact dermatitis. Med Clin North Am 2006
Jan;90(1):169-85.
(3) de Groot AC, Frosch PJ. Adverse reactions to fragrances. A clinical
review. Contact Dermatitis 1997 Feb;36(2):57-86.
(4) Johansen JD. Fragrance contact allergy: a clinical review. Am J Clin
Dermatol 2003;4(11):789-98.
(5) Schnuch A, Geier J, Uter W, Frosch PJ, Lehmacher W, Aberer W, et al.
National rates and regional differences in sensitization to allergens of the
standard series. Population-adjusted frequencies of sensitization (PAFS) in
40,000 patients from a multicenter study (IVDK). Contact Dermatitis 1997
Nov;37(5):200-9.
(6) Brasch J, Becker D, Aberer W, Bircher A, Kranke B, zer-Furst S, et al.
Contact dermatitis. J Dtsch Dermatol Ges 2007 Oct;5(10):943-51.
(7) Mark BJ, Slavin RG. Allergic contact dermatitis. Med Clin North Am 2006
Jan;90(1):169-85.
(8) Bakkali F, Averbeck S, Averbeck D, Idaomar M. Biological effects of
essential oils - A review. Food Chem Toxicol 2008 Feb;46(2):446-75.
(9) Basketter DA, Allenby CF. Studies of the quenching phenomenon in delayed
contact hypersensitivity reactions. Contact Dermatitis 1991 Sep;25(3):160-71.

Primary Objective:
What is the frequency of positive patch test reactions to the 26 declarable
fragrance allergens in fragrance mix I and/or II positive participants?

Secondary Objectives:
Do Weleda cosmetic products containing essential oils, provoke allergic contact
dermatitis skin reactions in fragrance mix I and/or II positive participants?
Does increment of concentration of essential oils in Weleda cosmetic products,
still below concentrations used in commercial patch test material, provoke more
patch test reactions than the original product?
Do concomitant patch test reactions occur among fragrance allergens?
If applicable, which concomitant reaction patterns are significant?
Do eugenol containing essential oils provoke less contact allergy than eugenol,
tested solitary in the same concentration?
Does supplementation of the antioxidant Vitamin E to eugenol reduce skin test
reactivity to eugenol?
Do participants, who react to Weleda cosmetic products, have increased skin
irritability in comparison to participants non-reacting to Weleda cosmetic
products?

Mono-center double blind prospective volunteer study.

All participants are offered patch tests, a skin irritability test and a
repeated open application test (user test) with (components of) cosmetics.

Participants have to invest time to come to the dermatology outpatient clinic
(5 visits, each of approximately 30 minuts). (Minor) discomforts can occur from
the patch tests, skin irritability test and repeated open application test. For
example local itching, redness of the skin, sometimes with vesicles, can occur.
The study procedures are routine procedures in dermatological diagnostics. The
substances to be tested in this study are either routine diagnostic substances
or commercially available cosmetic products or a combination of them. These
substances have to remain attached to the skin and therefore the skin of the
back and arm should not be showered during the first visit 1 until visit 3 of
the study. Sporting should also be avoided. After visit 3 we will ask not to
sport and wet the back and the arm during showers. Light showers are permitted.
Participants could benefit from the additional advice they receive about their
allergy. They will have gained more specific information about their allergy,
substances to which they have to avoid skin contact to and, if possible, safe
alternatives for cosmetic products.