Internalize Info of the Week: Lichen Planus Buzzwords

Lichen planus is an autoimmune disease that can cause a rash on the skin, mucous membranes of the mouth and genital area, nails, and head. The exact cause of this condition is not known.

There are several key buzzwords associated with lichen planus which will be defined in this post. The entire pathogenesis will not be discussed here. The definitions of these buzzwords are important to know because they can help clinically by making the diagnosis and help academically by making the correct answer choice on board exams.

Wickham’s Striae: This term is an eponym, named after Louis Frédéric Wickham. It describes the appearance of the material located on the surface of the papular rash or located in the mucous membranes of the mouth. The material is lacy, white or grey in color, and made up of thin lines or dots. The exact cause for the striae to appear is not known, but is thought to possibly be due to activation of the epidermis to produce more cells and/or a loss of blood supply to the dermis.

Koebner Phenomenon: This term is also an eponym, named after Heinrich Koebner, and is likewise known as the isomorphic response. It describes the occurrence of new lesions that appear around a wound or site of irritation. It is seen not only in lichen planus, but also in other conditions such as psoriasis, warts, and molluscum contagiosum.

Saw-Tooth Appearance: This term refers to how a biopsy specimen of the skin appears when looked at under the microscope. When viewing the area where the epidermis and dermis come together, it looks more irregular and bumpy giving the impression of the teeth on a saw.

Civatte Bodies: This term is another eponym, named after Achille Civatte. They are also known as colloid bodies. They describe the appearance of cells located in the epidermis or dermis that have a dark-staining circular appearance with no nucleus. They are created from dying skin cells.

These are the main medical buzzwords associated with lichen planus. Knowing these terms will help differentiate lichen planus from other diseases in your differential.

Sources:

Ismail, Sumairi B., Satish K. S. Kumar, and Rosnah B. Zain. "Oral Lichen Planus and Lichenoid Reactions: Etiopathogenesis, Diagnosis, Management and Malignant Transformation." Journal of Oral Science 49.2 (2007): 89-106. Nihon University School of Dentistry. Web. 12 Dec. 2011. <http://www.jstage.jst.go.jp/article/josnusd/49/2/49_89/_article>.

Katta, Rajani. "Lichen Planus." American Family Physician 61.11 (2000): 3319-324. AAFP.org. American Academy of Family Physicians. Web. 12 Dec. 2011. <http://www.aafp.org/afp/2000/0601/p3319.html>.

"Koebner Phenomenon." The Free Dictionary Medical Dictionary. Farlex. Web. 12 Dec. 2011. <http://medical-dictionary.thefreedictionary.com/Koebner+phenomenon>.

Sachdeva, Silonie, Pranav Kapoor, and Shabina Sachdeva. "Wickham Striae: Etiopathogenensis and Clinical Significance." Indian Journal of Dermatology 56.4 (2011): 442. PubMed. Web. 12 Dec. 2011. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3179016/?tool=pubmed>.

"Sawtooth Pattern." The Free Dictionary Medical Dictionary. Farlex. Web. 12 Dec. 2011. <http://medical-dictionary.thefreedictionary.com/Sawtooth+Pattern>.

Stone, M. S., and T. L. Ray. "DermPathTutor-Civatte." University of Iowa Carver College of Medicine. Sept. 1995. Web. 12 Dec. 2011. <http://www.healthcare.uiowa.edu/dermatology/DPT/Civatte.htm>.

"Whonamedit - Civatte's Bodies." Whonamedit - Dictionary of Medical Eponyms. Web. 12 Dec. 2011. <http://www.whonamedit.com/synd.cfm/3422.html>.

"Whonamedit - Wickham's Striae." Whonamedit - Dictionary of Medical Eponyms. Web. 12 Dec. 2011. <http://www.whonamedit.com/synd.cfm/2520.html>.

Williams, Gary, and Murray Karcher. "Skin Lesions: Koebner Phenomenon." Department of Pediatrics. University of Wisconsin Madison. Web. 12 Dec. 2011. <http://www.pediatrics.wisc.edu/education/derm/tutc/koebner.html>.