Petechia, Purpura, & Vasculitis

Here is a link to a PDF document from UCSF Medical School reviewing palpable purpura. It’s a good review for a non-dermatologist. Take a look . . . Petechia, Purpura,  and Vasculitis

Herpes Zoster

Pain often precedes the rash in a majority of patients; it is typically distributed in a dermatomal fashion and is usually restricted to one dermatome, with possible involvement of adjacent dermatomes.  The patients describe the pain as “burning,” “throbbing,” or “stabbing.” It may be severe, constant,  persistent, itchy, and misdiagnosed as angina if symptomatic in… Read more »


Patients frequently present with intense itching generally at night (also check for bed bugs) associated with a “rash.” A short elevated pink and tortuous line, or serpiginous track in the superficial epidermis, with a small vesicle at the tip is known as a burrow; this is pathognomonic of scabies. Treatment: Treat everyone simultaneously Bed linen… Read more »

Livedo Reticularis

When you see this in a question, think of Athreroemboli Vasculitis (SLE) Hyperviscosity Syndrome (Antiphospholipid Syndrome) If you see it in a patient, it’s probably nothing . . . unless there are associated symptoms of pain or ulcer development.