Board review: skin clues to systemic disease
Classic associations that should trigger targeted systemic assessment rather than memorisation alone.
Updated: 2026-09-13
Written for clinicians and medical students
This section is a teaching reference for doctors, residents and medical students. It is not patient guidance and not a substitute for clinical examination, and it must not be used for self treatment.
High-yield associations
- Acanthosis nigricans suggests insulin resistance; abrupt extensive disease in a lean older adult warrants evaluation for an underlying malignancy [1].
- Dermatomyositis combines characteristic skin signs with inflammatory myopathy. Adult-onset disease requires age-appropriate malignancy assessment guided by risk factors [2].
- Necrobiosis lipoidica, diabetic dermopathy and recurrent candidiasis can accompany diabetes, but none alone establishes the diagnosis.
- Eruptive xanthomas should prompt urgent fasting triglycerides because severe hypertriglyceridaemia can cause pancreatitis [1].
Reasoning rule
An association changes pre-test probability; it does not replace history, examination or confirmatory testing. In an examination answer, name the association, the specific symptom or sign you would seek, and the test that would alter management.