Psoriasis or crusted scabies

Area of Science:

• Dermatology
• Parasitology

Background:

• Psoriasis and crusted scabies can present with similar skin symptoms, leading to diagnostic challenges.
• A 67-year-old woman initially diagnosed with psoriasis was treated with topical calcipotriol and methotrexate.
• The patient's husband had a history of chronic pruritus, suspected to be scabies.

Observation:

• The patient presented with a year-long history of nail thickening and a non-itchy erythematous scaly eruption on the fingertips.
• A diagnostic review prompted by the husband's persistent pruritus led to further investigation.
• Skin scraping confirmed the presence of numerous mites, indicating crusted scabies.

Findings:

• The patient was successfully treated with topical permethrin, keratolytics, and oral ivermectin.
• This case underscores the importance of considering scabies in differential diagnoses, especially with a history of exposure.
• Literature review on crusted scabies management and recommendations are provided.

Implications:

• Accurate and timely diagnosis of crusted scabies is essential to prevent its spread and manage effectively.
• Crusted scabies requires a different treatment approach than psoriasis, emphasizing the need for careful dermatological evaluation.
• This case highlights the importance of considering the patient's social and family history in complex dermatological presentations.