Related Experiment Video
Updated: Apr 6, 2026
![Chemical-Induced Skin Carcinogenesis Model Using Dimethylbenz[a]Anthracene and 12-O-Tetradecanoyl Phorbol-13-Acetate DMBA-TPA](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60445.jpg&w=3840&q=50)
Chemical-Induced Skin Carcinogenesis Model Using Dimethylbenz[a]Anthracene and 12-O-Tetradecanoyl Phorbol-13-Acetate DMBA-TPA
Published on: December 19, 2019
Low-dose methotrexate-induced skin toxicity: Keratinocyte dystrophy as a histologic marker
Julie Delyon1, Nicolas Ortonne2, Emmanuel Benayoun3
1Département de Dermatologie, Assistance Publique-Hôpitaux de Paris (AP-HP) Hôpitaux universitaires Henri Mondor, Créteil, France.
Background:
Skin toxicity during low-dose methotrexate therapy is rare, ill described, and reported to have nonspecific histologic characteristics. Thus, misdiagnosis is common in patients with mucosal ulcers and/or skin erosions related to low-dose methotrexate.
Objective:
We sought to describe the features of skin toxicity induced by low-dose methotrexate.
Methods:
We evaluated the clinical and histologic features in 5 patients who experienced skin toxicity induced by low-dose methotrexate between 2011 and 2013.
Results:
All 5 patients had acute mucosal ulcers, 4 had moderately abnormal blood cell counts, and 3 had skin erosions. In 3 patients, methotrexate dosage or dosing-schedule errors were identified. No other contributing factors (eg, renal dysfunction or interacting drugs) were identified. Mucocutaneous biopsy specimens consistently showed multiple dystrophic keratinocytes.
Limitations:
We studied only 5 patients and obtained no sensitivity or specificity data on the diagnostic value of keratinocyte dystrophy.
Conclusion:
Keratinocyte dystrophy may help to diagnose skin toxicity of low-dose methotrexate, even in the absence of known risk factors or methotrexate administration errors. Studies of the diagnostic performance of this histologic sign are needed.
Related Concept Videos
The Intrinsic Apoptotic Pathway
Acne Infection
Drug Toxicity: Dose-Dependent Reactions
Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
Drug Toxicity: Allergic Reactions

