Certain skin lesions are important as they give clue to some underlying illness
Purplish striae is seen over the lower, anterior abdominal wall in Cushing's syndrome.
Erythema marginatum is a cutaneous sign in rheumatic fever.
Purpuras, ecchymosis are seen in ITP, Henoch-Schonlein purpura, coagulation defects, Leukemias.
Adenoma sebaceum ,Shagreen patch and Ash leaf macules are seen in Tuberous sclerosis
Hemangiomas present externally may also be present in the CNS.
Telangiectasia are seen in ataxia telangiectasia .Multiple telangiectasias are seen in Osler-Rendu Weber syndrome.
Osler-Rendu Weber syndrome there is AV malformations found in- Lung
- Liver
- CNS
- Mucous membranes.
Palmar erythema is seen in
- Decompensated liver disease
- Chronic febrile illness
- Chronic leukemias
- Polycythemia
- Rheumatoid arthritis
- Thyrotoxicosis
- Chronic alcohol intake
- Physiological states like pregnancy.
Multiple neurofibromas are seen in von Recklinghausen's disease
Xanthomas indicate underlying Hyperlipidemia
Malignant tumours of the skin are Squamous cell carcinoma, basal cell carcinoma, malignant melanoma.
Pigmentation of the mucous membrane of the oral cavity is seen in
Addison's disease, and in Peutz-Jeghers syndrome which is associated with perioral pigmentation and polyposis of colon.
A tuft of hair or a lipoma over the lower lumbar region in the back may give clue to the presence of spina bifida.
