An Unusual Presentation of Lichen Planus

Area of Science:

• Dermatology
• Internal Medicine

Background:

• Lichen planus is a chronic inflammatory condition affecting skin, scalp, nails, and mucous membranes.
• The classic presentation involves pruritic, purple, polygonal, planar papules and plaques, often referred to as the six P's.

Observation:

• A 64-year-old female presented with a two-week history of thigh swelling, erythema, tenderness, hyperkeratotic plaques, and blisters.
• Initial presentation mimicked bacterial cellulitis or pyoderma gangrenosum exacerbation, leading to empirical antibiotic and antiviral treatment with no improvement.

Findings:

• A clinical diagnosis of psoriasiform dermatitis was made, and a skin biopsy was obtained.
• Prompt improvement with oral prednisone suggested a diagnosis of lichen planus, specifically the vesiculobullous subtype.
• Skin biopsy results were consistent with chronic psoriasiform dermatitis, with lichen planus as a primary differential diagnosis.

Implications:

• This case underscores the importance of recognizing rare clinical variants of lichen planus, such as the vesiculobullous subtype presenting as cellulitis.
• Effective management requires prompt diagnosis and the use of corticosteroids, as antibiotic treatment alone is insufficient.
• Awareness of these rare presentations can lead to earlier diagnosis, altered management strategies, and improved patient outcomes.