There are a number of bullous diseases other than pemphigus and bullous pemphigoid that are important to recognize. Porphyria cutanea tarda is a porphyria that has no extracutaneous manifestations (Figures 186-1, 186-2, and 186-3). Dystrophic epidermolysis bullosa belongs to a family of inherited diseases where blister formation can be caused by even minor skin trauma. PLEVA (pityriasis lichenoides et varioliformis acuta) is a minor cutaneous lymphoid dyscrasia that can appear suddenly and persist for weeks to months. Dermatitis herpetiformis is a recurrent eruption that is usually associated with gluten and diet-related enteropathies.
Porphyria cutanea tarda in a middle-aged woman. (Courtesy of Lewis Rose, MD.)
Porphyria cutanea tarda in a man with hepatitis C. (Courtesy of the University of Texas Health Sciences Center, Division of Dermatology.)
Porphyria cutanea tarda in a man with hepatitis C and alcohol abuse. (Courtesy of Richard P. Usatine, MD.)
A middle-aged woman presented with tense blisters on the dorsum of her hand (Figure 186-1). One bulla was intact and the others had ruptured, showing erosions. Work-up showed elevated porphyrins in the urine (which fluoresced orange-red under a Wood lamp) and the patient was diagnosed with porphyria cutanea tarda.
- Porphyria cutanea tarda (PCT) occurs mostly in middle-aged adults (typically 30 to 50 years of age) and is rare in children.
- It is especially likely to occur in women on oral contraceptives and in men on estrogen therapy for prostate cancer.1
- Alcohol, pesticides, and chloroquine have been implicated as chemicals that induce PCT.1
- PCT is equally common in both genders.
- There is an increased incidence of PCT in persons with hepatitis C (Figures 186-2 and 186-3).
Etiology and Pathophysiology
- The porphyrias are a family of illnesses caused by various metabolic derangements in the metabolism of porphyrin, the chemical backbone of hemoglobin. Whereas the other porphyrias (acute intermittent porphyria and variegate porphyria) are associated with well-known systemic manifestations (abdominal pain, peripheral neuropathy, and pulmonary complications), PCT has no extracutaneous manifestations. Photosensitivity is seen (as with variegate porphyria). PCT is associated with a reduction in hepatic uroporphyrin decarboxylase.
- Hepatitis C.
- Alcohol-induced liver injury.
The classic presentation is that of blistering (vesicles and tense bullae) on photosensitive “fragile skin” (similar to epidermolysis bullosa). Scleroderma-like heliotrope suffusion of the eyelids and face may be seen. As the blisters heal, the skin takes on ...