Persistent cutaneous hyperpigmentation due to hydroxychloroquinone one year after therapy discontinuation

Area of Science:

• Dermatology
• Rheumatology
• Pharmacology

Background:

• Hydroxychloroquine (HCQ) is widely used for malaria, rheumatologic, and dermatologic conditions due to its anti-inflammatory and immune-modulating effects.
• Mucocutaneous bluish-gray dyschromia is a rare adverse effect associated with HCQ treatment.
• Limited data exists on the duration and extent of HCQ-induced dyschromia after drug cessation.

Observation:

• This report details a patient experiencing extensive, diffuse bluish-gray dyschromia on the extremities.
• The dyschromia was attributed to hydroxychloroquine therapy.

Findings:

• One year after discontinuing hydroxychloroquine, the patient exhibited minimal resolution of the extensive dyschromia.
• This case contrasts with previous reports, which typically described smaller, focal areas of discoloration.

Implications:

• The findings suggest that extensive HCQ-induced dyschromia may be persistent and show limited improvement post-discontinuation.
• This case underscores the importance of monitoring for and documenting rare, extensive side effects of commonly prescribed medications like HCQ.
• Further research is warranted to understand the pathophysiology and long-term prognosis of severe hydroxychloroquine-induced dyschromia.