Psoriasis vs. Eczema: A Dermatological Diagnosis Guide for Itchy Erythematous Scaly Plaques and Topical Treatments

The differential diagnosis between psoriasis and eczema is a common challenge in dermatological practice. Both conditions are chronic inflammatory skin diseases that can present with itching and erythematous scaly plaques, but their etiologies and treatments vary significantly. An accurate diagnosis is crucial for implementing an appropriate topical treatment and improving the patient's quality of life.

Diving Deeper into Differential Diagnosis

Psoriasis is characterized by well-defined, erythematous plaques covered with silvery scales. These plaques are often located on extensor surfaces such as elbows and knees. In contrast, eczema, also known as atopic dermatitis, presents with more diffuse lesions, often accompanied by vesicles and exudation, and is frequently localized in flexural areas such as the folds of the elbows and behind the knees.

The use of diagnostic tools such as dermatoscopy can be helpful in differentiating between these conditions. In a comparative study, it was observed that palmoplantar psoriasis presents regular vessels and white scales, while palmoplantar eczema shows yellowish scales and irregular vessels [1]. Additionally, the expression of certain molecular markers, such as NOS2 and CCL27, may assist in distinguishing between both diseases in clinically uncertain cases [2].

Histopathological evaluation can also provide valuable clues. A recent analysis highlighted the utility of biopsies and adhesive strips to molecularly differentiate between psoriasis and eczema, showing high sensitivity and specificity [3]. Furthermore, capillaroscopy has proven to be an effective tool for identifying significant morphological changes in lesions of psoriasis and eczema [4].

Conclusions

The differential diagnosis between psoriasis and eczema is essential for the proper management of these conditions. The integration of advanced techniques such as dermatoscopy, molecular evaluation, and capillaroscopy can significantly enhance diagnostic accuracy. By understanding the clinical and pathological differences between these diseases, dermatologists can offer more personalized and effective treatments, thereby improving outcomes for patients.

Referencias

• [1] Dermoscopy in the Diagnosis of Palmoplantar Eczema and Palmoplantar Psoriasis: A Cross-Sectional, Comparative Study from a Tertiary Care Centre in North India
• [2] NOS2 and CCL27: clinical implications for psoriasis and eczema diagnosis and management
• [3] Gene Expression-Based Molecular Test as Diagnostic Aid for the Differential Diagnosis of Psoriasis and Eczema in Formalin-Fixed and Paraffin-Embedded Tissue, Microbiopsies, and Tape Strips
• [4] Evaluation of serum vascular endothelial growth factor level and findings of nailfold capillaroscopy by dermatoscope in the differential diagnosis of palmoplantar psoriasis and palmoplantar eczema

Created 6/1/2025