Sometimes you can get a reaction to a product or ingredient and not realize that the ingredient is fairly well known as an allergen.
People often ask me what I know about an ingredient because they know I will search for the information if I cannot reply right away. I was recently asked about what someone recalled regarding shea butter and could not find in the current LHC threads. That is because that particular thread is archived. This is it, the LHC thread, where quidscrbis describes her severe allergic reaction to shea butter, a painful rash that lasted weeks.
Update November 16, 2012
Unfortunately, the LHC link above no longer works and at this time, I am unable to update it. Shea butter being a natural botanical product will have variations in constituents.
As it turns out, there is more to shea butter than is commonly known. I have seen warnings online that it should not be used on broken skin. See this link for peer-reviewed information on shea butter and its safety and cautions.
Then there is the question of labelling. This company, puts a warning on its label, for unrefined shea butter with essential oils.
As to reports online that shea butter is good for irritated skin, this 1996 study reported that canola oil actually worked better than the other lipids tested, which included shea butter.
Added June 27,2015
See also regarding shea products quality
2011
"Effect of storage conditions on
microbiological and physicochemical quality of shea butter"
"The effect of storage duration and packaging materials on microbiological and physicochemical qualities of shea butter revealed the necessity to change some packaging materials used in the production sites."
2014
"Nutritional composition of shea products and chemical properties of shea butter: a review."
http://www.pubfacts.com/detail/24261539/Nutritional-composition-of-shea-products-and-chemical-properties-of-shea-butter-a-review
"Fat extraction is mainly done by traditional methods ... roasting and pressing of the kernels ... fat (butter) is used in food preparation and medicinal and cosmetics industries ... biochemical properties indicate some antioxidant and anti-inflammatory activities. Large variations are observed in the reported values for the composition of shea products. Recommendations for future research are presented to improve the quality and the shelf-life of the butter ... more attention should be given to the accuracy and precision in experimental analyses to obtain more reliable information about biological variation."
2014
"Nutritional composition of shea products and chemical properties of shea butter: a review."
http://www.pubfacts.com/detail/24261539/Nutritional-composition-of-shea-products-and-chemical-properties-of-shea-butter-a-review
"Fat extraction is mainly done by traditional methods ... roasting and pressing of the kernels ... fat (butter) is used in food preparation and medicinal and cosmetics industries ... biochemical properties indicate some antioxidant and anti-inflammatory activities. Large variations are observed in the reported values for the composition of shea products. Recommendations for future research are presented to improve the quality and the shelf-life of the butter ... more attention should be given to the accuracy and precision in experimental analyses to obtain more reliable information about biological variation."
2014
"Coping
with the Upheavals of Globalization in the Shea Value Chain: The Maintenance
and Relevance of Upstream Shea Nut Supply Chain Organization in Western Burkina
Faso"
"If mandatory labeling implies stricter social and environmental requirements by the final buyers, it may also entail a shift in the organization of the shea value chain."