When you think of allergies, the first thing that comes to mind is probably seasonal allergies, but there are a handful of strange allergies can be much harder to avoid than pollens. Hosted by: Michael Aranda ---------- Support SciShow by becoming a patron on Patreon: www.patreon.com/scishow ---------- Dooblydoo thanks go to the following Patreon supporters: Lazarus G, Kelly Landrum Jones, Sam Lutfi, Kevin Knupp, Nicholas Smith, D.A. Noe, alexander wadsworth, سلطان الخليفي, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Charles Southerland, Bader AlGhamdi, James Harshaw, Patrick Merrithew, Patrick D. Ashmore, Candy, Tim Curwick, charles george, Saul, Mark Terrio-Cameron, Viraansh Bhanushali, Kevin Bealer, Philippe von Bergen, Chris Peters, Justin Lentz ---------- Looking for SciShow elsewhere on the internet? Facebook: www.facebook.com/scishow Twitter: www.twitter.com/scishow Tumblr: scishow.tumblr.com Instagram: instagram.com/thescishow ---------- Sources: Sources: www.researchgate.net/publication/276147913_Physical_urticaria_Review_on_classification_triggers_and_management_with_special_focus_on_prevalence_including_a_meta-analysis www.ncbi.nlm.nih.gov/pmc/articles/PMC2492902/ www.pcds.org.uk/clinical-guidance/urticaria-physical-urticaria www.merckmanuals.com/professional/dermatologic-disorders/approach-to-the-dermatologic-patient/urticaria www.merckmanuals.com/professional/immunology-allergic-disorders/allergic,-autoimmune,-and-other-hypersensitivity-disorders/overview-of-allergic-and-atopic-disorders emedicine.medscape.com/article/762917-overview abcnews.go.com/Health/AllergiesNews/story?id=7401149&page=1 mosaicscience.com/story/why-do-we-have-allergies/ dermographism www.dermnetnz.org/topics/dermographism/ emedicine.medscape.com/article/1050294-overview www.ncbi.nlm.nih.gov/pubmed/16405609 vibration ghr.nlm.nih.gov/condition/vibratory-urticaria#genes www.nih.gov/news-events/news-releases/nih-scientists-discover-genetic-cause-rare-allergy-vibration water rarediseases.info.nih.gov/diseases/10901/aquagenic-urticaria www.bbc.com/future/story/20160915-the-woman-who-is-allergic-to-water www.sciencealert.com/here-s-what-happens-if-you-develop-an-allergy-to-water onlinelibrary.wiley.com/doi/10.1111/j.1525-1470.2012.01801.x/abstract exercise emedicine.medscape.com/article/886641-overview#showall www.ncbi.nlm.nih.gov/pmc/articles/PMC3020292/ www.aafp.org/afp/2001/1015/p1367.html semen clinicalmolecularallergy.biomedcentral.com/articles/10.1186/1476-7961-6-13 www.uptodate.com/contents/allergic-reactions-to-seminal-plasma www.issm.info/sexual-health-qa/what-is-a-sperm-allergy/ www.tandfonline.com/doi/abs/10.3810/pgm.2011.01.2253 www.annallergy.org/article/S1081-1206(13)00005-7/abstract www.allergologyinternational.com/article/S1323-8930(17)30110-7/fulltext sciencealert.com/rare-post-orgasm-illness-is-real-and-warrants-further-research-study-finds-pois-semen rarediseases.info.nih.gov/diseases/10809/postorgasmic-illness-syndrome www.jsm.jsexmed.org/article/S1743-6095(15)33455-X/fulltext www.nature.com/articles/nrurol.2011.17 progesterone rarediseases.info.nih.gov/diseases/9139/autoimmune-progesterone-dermatitis rarediseases.info.nih.gov/diseases/9139/autoimmune-progesterone-dermatitis/cases/33524 www.medscape.com/viewarticle/712365 www.annallergy.org/article/S1081-1206(10)61838-8/abstract www.ncbi.nlm.nih.gov/pmc/articles/PMC3423662/ www.ncbi.nlm.nih.gov/pmc/articles/PMC509283/ www.dermnetnz.org/topics/autoimmune-progesterone-dermatitis Image Sources: commons.wikimedia.org/wiki/File:Skin_writing01.jpg upload.wikimedia.org/wikipedia/commons/a/a0/SMCpolyhydroxysmall.jpg en.wikipedia.org/wiki/Histamine#/media/File:Histamine.svg commons.wikimedia.org/wiki/File:PSA_KLK3_PDB_2ZCK.png en.wikipedia.org/wiki/Progesterone#/media/File:Progesterone-3D-balls.png