Autoimmune diseases

Do You Recognize These Skin Signs of Autoimmune Disease?

JOE R. MONROE, PA, MPAS
Dawkins Dermatology, Oklahoma City, Oklahoma

Joe R. Monroe is a physician assistant who is affiliated with Dawkins Dermatology in Oklahoma City, Oklahoma. He is also the founder and former president of the Society of Dermatology Physician Assistants, and he teaches and writes extensively about dermatologic topics.

 

Case 1: Perioral Rhagades

A 64-year-old woman presents with these changes in her facial skin. At first, the skin became more firm and waxy, then her lips began to retract from her teeth; rhagades appeared in the perioral skin. She also has a 6-year history of Raynaud phenomenon and sclerodactyly. The latter eventually advanced to the so-called clawhand, a flexion deformity that is very disabling.

scleroderma

What do you suspect underlies these skin changes?

(Answer and discussion on next page)

ANSWER—Case 1: Scleroderma

Scleroderma is caused by excess deposition of collagen in the dermis. This uncommon systemic disease is thought to be of autoimmune origin. It may affect only limited areas of skin with little, if any, internal involvement. In this patient, however, virtually all of her skin, as well as internal organs, was involved.

sclerodermaSclerotic esophageal changes have made it impossible for her to eat solid food. Since placement of an indwelling gastric feeding tube, she has been gradually losing weight; she currently weighs less than 40.5 kg (90 lb). She also has chronic renal failure and pulmonary involvement. Her prognosis is quite poor. She has already outlived the 5-year 50% survival rate.

Diagnosis of scleroderma requires at least the presence of Raynaud phenomenon, sclerodactyly, and a positive antinuclear antibody, in the absence of signs of other connective-tissue diseases. Dermatologic and rheumatologic consultation may be necessary, because many patients have features of multiple conditions that require further laboratory workup for diagnosis.

In addition to treatment of specific problems, such as H2 blockers for esophageal reflux, most patients are given penicillamine, which slows down the production of collagen. Because penicillamine therapy is associated with significant adverse effects and a 30% dropout rate, many patients are also treated with corticosteroids, interferon, cyclosporine, and extracorporeal photochemotherapy. Responses to all of these adjuvant therapies are inconsistent. ■

(Case 2 on next page)

Case 2: Persistent Blisters

For several weeks, a 49-year-old woman has had large, tense, persistent blisters on the arms and trunk. She also has annular papulovesicular and urticarial lesions in these areas. 

pemphigoid

What is the likely cause of these lesions?

(Answer and discussion on next page)

ANSWER—Case 2: Bullous pemphigoid

pemphigoidHematoxylin and eosin staining and direct immunofluorescence of biopsy specimens from perilesional and uninvolved skin confirmed the diagnosis of bullous pemphigoid. This autoimmune disease generally affects persons older than 60 years. It is associated with presumably causative autoantibody production, as manifested by either the deposition of IgG along the basement membrane zone or, as in this patient, the deposition of C3.

The main condition in the differential diagnosis is pemphigus, which is characterized by weakness and malaise and by flaccid blisters that break easily. Obtaining biopsy specimens from both perilesional and uninvolved skin is necessary to distinguish bullous pemphigoid from its other mimics, such as erythema multiforme, acquired epidermolysis bullosa, bullosa diabeticorum, and dermatitis herpetiformis.

This patient was treated with prednisone, 40 mg twice a day for a week, which was tapered over a 3-week period and then replaced with dapsone. The prognosis is usually excellent, because the disorder is often self-limited. ■