Uploaded May 2025 | Updated September 2026, 2 weeks ago

---

Erythema Nodosum (Red Lumps on Legs) | Causes, Signs & Symptoms, Diagnosis, Treatment

Erythema Nodosum is a skin condition involving red “lumps” or nodules (along with plaques), most often on the shins of the legs. Erythema Nodosum can be a common dermatologic finding in many conditions, including being the most common skin finding in Crohn’s disease, but also occurring during some infections with bacteria like streptococcus, salmonella and shigella. In this lesson, we discuss the many causes of Erythema Nodosum, including infectious causes, medications, autoimmune conditions and others as well.

I hope you find this lesson helpful. If you do, please like and subscribe for more lessons like this one!

JJ

REFERENCES:
emedicine.medscape.com/article/1081633-overview

**MEDICAL LEGAL DISCLAIMER**: JJ Medicine does not provide medical advice, and the information available on this channel does not offer a diagnosis or advice regarding treatment. Information presented in these lessons is for educational purposes ONLY, and information presented here is not to be used as an alternative to a healthcare professional’s diagnosis and treatment of any person/animal. Only a physician or other licensed healthcare professional are able to determine the requirement for medical assistance to be given to a patient. Please seek the advice of your physician or other licensed healthcare provider if you have any questions regarding a medical condition.

*AFFILIATE DISCLAIMER: This YouTube Channel uses affiliate links and may earn a commission from associated sales.

*IMAGE DISCLAIMER: The content (ex. images) used in this lesson are used in accordance with Fair Use laws and are intended for educational/teaching purposes only*

*Subscribe for more free medical lessons* youtube.com/channel/UCFPvnkCZbHfBvV8ApBBE0vA?sub_confirmation=1

-------------------------------------------------------------------------------------------------------------
For books and more information on these topics
amazon.com/shop/jjmedicine

Support future lessons and lectures ➜ patreon.com/jjmedicine

Check out the best tool to help grow your YouTube channel (it’s helped me!)
tubebuddy.com/jjmedicine

Follow me on Twitter! ➜ twitter.com/JJ_Medicine

Come join me on Facebook! ➜ facebook.com/JJ-Medicine-100642648161192

------------------------------------------------------------------------------------------------------------
*Check Out Some of My Other Lessons*

Medical Terminology - The Basics - Lesson 1:
youtube.com/watch?v=04Wh2E9oNug

Infectious Disease Playlist
youtube.com/playlist?list=PLRjNoiRtdFwW0Bkc6c66uDACkzotaK26b

Dermatology Playlist
youtube.com/playlist?list=PLRjNoiRtdFwW3dgORRNmk_MZvnWpZx_lW

Pharmacology Playlist
youtube.com/playlist?list=PLRjNoiRtdFwWPWcV9lZTh-Qxv0gYakQXR

Hematology Playlist
youtube.com/playlist?list=PLRjNoiRtdFwW8Ajo1dmxdj4EYEKcbtGju

Rheumatology Playlist
youtube.com/playlist?list=PLRjNoiRtdFwWDvuhasXsuTFXJp05wwUle

Endocrinology Playlist
youtube.com/playlist?list=PLRjNoiRtdFwUuRSzhploohnaWVvbVZ7ZP

Nephrology Playlist
youtube.com/playlist?list=PLRjNoiRtdFwXRSwrFQK5WwWZLk1Las8v8

Fatty Acid Synthesis Pathway:
youtube.com/watch?v=WuQS_LpNMzo

Wnt/B Catenin Signaling Pathway:
youtube.com/watch?v=NGVP4J9jpgs

Upper vs. Lower Motor Neuron Lesions:
youtube.com/watch?v=itNd74V53ng

Lesson on the Purine Synthesis and Salvage Pathway:
youtube.com/watch?v=e2KFVvI8Akk

Gastrulation | Formation of Germ Layers:
youtube.com/watch?v=d6Kkn0SECJ4

Introductory lesson on Autophagy (Macroautophagy):
youtube.com/watch?v=UmSVKzHc5yA