Related Experiment Video
Updated: Oct 17, 2025

Basophil Activation Test for Investigation of IgE-Mediated Mechanisms in Drug Hypersensitivity
Published on: September 16, 2011
Pityriasis lichenoides-like drug reaction with numerous eosinophils
Saira Agarwala1, Farhaan Hafeez2
1Temple/St. Luke's School of Medicine Bethlehem, Palestine.
Abstract:
Pityriasis lichenoides-like drug reactions simulate pityriasis lichenoides clinically and histopathologically, though important differences exist. As a rule, pityriasis lichenoides has minimal to no eosinophils. However, this case illustrates that pityriasis lichenoides-like drug reaction can present with numerous eosinophils. This, in our experience is not rare, but contrasts with clinical reports in the literature that describe pityriasis lichenoides-like drug reactions with minimal to no eosinophils in the infiltrate. While similar, distinguishing these diseases is important given that pityriasis lichenoides is a lymphoproliferative disorder with a more protracted clinical course that is difficult to treat. We provide histopathological clues to aid in this important distinction.
Related Concept Videos
Allergic Drug Reactions
Allergic Reactions
Antiasthma Drugs: Mast Cell Stabilizers and Anti-IgE Drugs
Mast cell stabilizers, such as cromolyn (also known as sodium cromoglycate) and nedocromil (Tilade), are effective drugs in asthma management. These stabilizers hinder histamine release by skillfully obstructing the activation of mast cells and other cellular entities. Notably, they navigate this task without...
Antiasthma Drugs: Leukotriene Modifiers
Leukotriene modifiers work through two distinct mechanisms:
Drugs for Treatment of Constipation-Predominant IBS
Drugs for Treatment of Diarrhea-Predominant IBS
Two specific drugs used in the treatment are alosetron (Lotronex) and eluxadoline (Viberzi). Alosetron, a 5-HT3 antagonist, works by slowing the movement of stools in the gut, reducing bowel...

