What is the Difference Between Lichen Planus and Lupus Erythematosus?

Lichen Planus (LP) and Systemic Lupus Erythematosus (SLE) are two distinct inflammatory skin conditions with different etiologies and clinical manifestations. Here are the main differences between the two:

1. Etiology: LP is a chronic inflammatory mucocutaneous disorder with an unknown etiology, while SLE is a prototypic autoimmune disease.
2. Cytokines: Both diseases involve cytokines in their pathogenesis, but they have different profiles. For example, the imbalance between Th-1 and Th-2 cytokine production plays an important role in the development of LP.
3. Clinical Manifestations: LP typically presents as mucocutaneous lesions, while SLE has a broader range of symptoms, including fatigue, joint pain, and systemic involvement.
4. Diagnosis: The diagnosis of LP is based on its clinical and histological appearance, while SLE requires the presence of specific criteria, such as malar rash, discoid rash, photosensitivity, oral ulcers, arthritis, and renal disease.
5. Treatment: The treatment for LP and SLE is different, as they have distinct pathogenic mechanisms.

In rare cases, an overlap syndrome between lupus erythematosus and lichen planus has been reported, which combines both the histologic and clinical features of these two conditions. However, this is an uncommon diagnostic entity and requires clinicopathologic correlation for accurate identification.

Comparative Table: Lichen Planus vs Lupus Erythematosus

Lichen planus and lupus erythematosus are both autoimmune disorders that affect the skin and mucous membranes, but they have distinct differences in their affected areas, symptoms, and underlying mechanisms. Here is a table summarizing the differences between the two:

In rare cases, there is a condition called cutaneous lupus erythematosus/lichen planus overlap syndrome, which has overlapping clinical and histologic features of both lichen planus and lupus erythematosus.