Papular Mucinosis Associated with Systemic Lupus Erythematosus

Area of Science:

• Dermatology
• Rheumatology
• Pathology

Background:

• Papulonodular mucinosis (PNM) is a rare variant of lupus erythematosus (LE).
• PNM is histologically defined by diffuse dermal mucin and lacks typical epidermal inflammatory changes.

Observation:

• A 32-year-old man presented with erythematous papules on his lower back, diagnosed as papulonodular mucinosis.
• The patient had systemic lupus erythematosus but no other characteristic LE skin manifestations like malar rash, discoid rash, or photosensitivity for two years.

Findings:

• The case demonstrates a distinct presentation of papulonodular mucinosis in a patient with systemic lupus erythematosus.
• Histological examination revealed diffuse dermal mucin without epidermal inflammation, consistent with PNM.

Implications:

• This case underscores the diverse cutaneous presentations of lupus erythematosus.
• Successful treatment with topical steroids, systemic antimalarials, and steroids led to remission of PNM without recurrence.
• Highlights the importance of considering rare variants in LE diagnosis and management.