Senear-Usher Syndrome or Coexistence of SLE with Pemphigus Vulgaris-A Case Report with Literature Review.

Senear-Usher syndrome, or pemphigus erythematosus (PE), is a rare autoimmune disorder characterized by the coexistence of features from both lupus erythematosus (LE) and pemphigus foliaceus (PF). We describe a 41-year-old patient initially diagnosed with cutaneous and then systemic lupus erythematosus (SLE), who after a few years developed new skin lesions: erythematous and erosive eruptions partially covered by crusts located on the trunk and flaccid blisters on the extremities. Direct immunofluorescence of perilesional skin revealed deposits of IgG in the intercellular space of the epidermis and granular deposits of C3 at the dermo-epidermal junction. Additional testing, revealing autoantibodies against the intercellular space of the epidermis, and direct immunofluorescence (DIF) examination allowed a diagnosis of pemphigus vulgaris coexisting with lupus. Further, DIF study revealed granular deposits of immunoglobulin G (IgG) in the intercellular spaces of the epidermis and granular deposits of the C3 along the basement membrane. Clinical appearance led to suspicion of Senear-Usher syndrome. in this patient. This case report explores the diagnostic challenges posed by the patient's overlapping symptoms and immunological findings, suggesting an infrequent manifestation of Senear-Usher syndrome or a combination of SLE and pemphigus vulgaris. The case highlights the complexity of chronic inflammatory skin diseases and the need for tailored treatment approaches in such cases. Despite temporary improvement, the patient experienced relapses. We performed a descriptive literature review of the case reports of PE published in the last 24 years and prepared a summary of the characteristics, emphasizing the importance of proper recognition, clinical features, and treatment of this uncommon syndrome.