A 68-Year-Old Woman with a Rash of Several Weeks’ Duration

Diagnosis

This patient was diagnosed with pityriasis rubra pilaris (PRP), which is characterized by an acute cutaneous eruption that is often accompanied by pruritis and/or pain. Etiology of PRP has not been clearly defined, though onset has been associated with myositis, myasthenia gravis, hypothyroidism, HIV, infection, and malignancy. In add ultraviolet exposure and minor skin trauma preceding onset has been reported. The majority of PRP cases are acquired (as opposed to heritable), the incidence of which occurs in two peaks: during the first and second decades of life, and during the sixth decade.

Learnings/What to Look for

• Classic cutaneous lesions include follicular papules on an erythematous base coalescing to form large, orange-red plaques with characteristic islands of sparing (as seen in this patient)
• PRP commonly (but not always) begins on the scalp and rapidly spreads in a craniocaudal direction and has the potential to quickly progress to erythroderma over several weeks’ time

Pearls for Urgent Care Management

• Emollients, topical lactic acid, topical corticosteroids, or oral retinoids may be useful in relieving symptoms
• Scaling may be reduced with emollients or 12% lactic acid with an occlusive dressing
• Patients resistant to topical treatments may require oral acitretin or methotrexate
• Advise patients that resolution may occur slowly over several years

Acknowledgment: Image and case presented by Visual Dx (www.VisualDx.com/JUCM).