Patch test usually tests only for true allergies.
Beside true allergies, you may also react to type 3 allergens, which are called intolerance.
For example, gluten intolerance and lactose intolerance and nightshade intolerance, Sugar
intolerance etc are not true allergies, but can also trigger Exfoliative cheilitis, eczema (atopic dermatitis), acne, Seborrheic Dermatitis
, folliculitis, psoriasis, etc.
Rosin, Colophony, Elastoplast allergy
Most commonly experienced as Elastoplast allergy
Colophony or rosin is a natural substance obtained from conifers. It is created from pine balsam during the making of turpentine. When the Turpentine
is distilled away, colophony (rosin) is the hard yellow residue left behind.
You may be familiar with Rosin in its natural form as used by players of stringed instruments but it is also widely used in the manufacture of other everyday items. Most people develop Colophony Allergy by being sensitised through the use of fabric sticking plasters (eg Elastoplast) as it is present in the adhesive.
Common sources of Colophony include:
mascara, rouge, soap, eyeshadow, shampoo, lipstick, nail varnish
medicated creams and ointments
wart treatment gels
fabric plasters, zinc oxide plaster on a roll, Micropore tape
adhesive tapes and fly papers
glue tackifiers eg on stamps and labels
paper (glossy paper is worse), magazines
the sticky sap of Christmas trees
Leylandii trees and pine forests
pine oil cleaners
rosin for stringed musical instruments
‘gripper’ for bowls, weight lifting and sports
dental cements and impression pastes
varnishes and glazes
surface coatings, sealing components
fan belts and clutches
In the European Union all products containing more than 1% colophony have to be labelled with an allergy warning.
Because colophony is found in such a wide variety of products, it is important to use ingredient-labelled products that do not list colophony or any of its synonyms on the label.
If you have become sensitised to colophony and need to avoid it watch out for its alternative names on ingredients lists:
methyl abietate alcohol
W-W wood rosin
If you are allergic to colophony you may also be allergic to turpentine, wood (spruce, pine balsam), wood tar, fragrance and Balsam of Peru.
You can now buy Hypoallergenic Plasters which do not use colophony in the adhesive.