Review Question - QID 204249

Given the patient's history of similar lesions, recent sun-exposure, and her otherwise healthy appearance, senile purpura is the most likely diagnosis.

Senile purpura occurs in >10% of individuals over the age of 50. The physical findings are dark purple, irregularly shaped patches that are approximately 1-4 cm in diameter with well demarcated margins. These lesions typically are found on the extensor surface of forearms and the dorsal surface of hands. As people age there is a loss of elastic fibers in perivascular connective tissue that makes blood vessels fragile. Subsequently, minor trauma and photodamage can lead to superficial vessel damage and the characteristic findings of senile purpura. These lesions can take up to 3 weeks to resolve and typically do not undergo the characteristic color changes as seen with normal bruising.

Ballas and Kraut discuss the work-up of bleeding and bruising of a patient. While senile purpura is on the differential, additional tests can be used if the diagnosis is in question. Initial tests should include a CBC with platelet count, peripheral blood smear, PT and PTT. Platelet function tests may also be considered.

Lawrence advocates therapies to treat the damage caused by sun exposure that may lead to the development of senile purpura. She advocates that the effects can be both psychological and physical by restoring the skin's natural barrier and affecting any premalignant lesions. Potential treatments are either topical applications of medication or surgical resurfacing.

Figure A demonstrates senile purpura on the forearm. Note the deep purple color and large size (several cm).

Incorrect answers:
Answer 1: The development of systemic amyloidosis is usually associated with another immune cell abnormality. Multiple myeloma is most commonly associated. There is nothing in the history to suggest this.
Answer 2: Pseudoxanthoma is an autosomal recessive disease. It appears as small, yellow plaques that are often found in the neck, axillae, and antecubital and popliteal fossae.
Answer 3: Scurvy often presents with corkscrew hairs and perifollicular papules and hemorrhages.
Answer 4: In addition to non-blanching macules or patches, this patient would likely present with nuchal rigidity and other systemic signs if she had meningococcemia.