Updated: 12/17/2021

Porphyria Cutanea Tarda

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  • Snapshot
    • A 25-year-old woman, on oral contraceptives, comes to the dermatologist’s office complaining of a rash on her hands, forearms, and face. On exam, her arms and dorsal hands are covered with oozing erosions and ulcers. Alongside these ulcers are patches of hyperpigmented skin. On questioning, we find that her mother has had similar episodes.
  • Introduction
    • Blistering cutaneous photosensitivity caused by hepatotoxic triggers
    • Autosomal dominant or sporadic defect in heme synthesis
      • deficiency of hepatic uroporphyrinogen decarboxylase
        • accumulation of uroporphyrin 1
    • Recurrent flares triggered by hepatotoxins that upregulate heme/P450 synthesis
      • alcohol and estrogen = most common triggers
      • viral hepatitis
      • HIV
      • iron
    • Associated conditions
      • alcoholism
      • liver disease
      • hemochromatosis
      • chronic hepatitis C
      • oral contraceptives
  • Epidemiology
    • Most common form of porphyria
    • Middle-aged men and women
    • Younger women on oral contraceptives
  • Presentation
    • Skin findings
      • skin fragility
      • erythema, edema, vesicles progressing to non-healing blisters, erosions, ulcers
        • in sun-exposed areas (face, neck, dorsal hands, forearms)
      • hypertrichosis of face
      • hyperpigmentation of skin
      • scleroderma-like plaques
    • Non-skin findings
      • no abdominal pain (as in other porphyrias)
      • red-brown urine (port-wine urine) from porphyrin pigment
  • Evaluation
    • Diagnosis by skin biopsy
      • subepidermal split (bullae)
      • linear, eosinophilic acid-Schifff positive globules ("Caterpillar bodies")
      • direct immunofluorescence
        • deposition of IgG, IgM, C3 in papillary dermis
    • Or diagnosis by urine
      • ↑ urine uroporphyrin levels (2-5x above coproporphyrins)
      • Wood’s lamp
        • distinctive orange-pink color due to ↑ uroporphyrin
    • To monitor
      • LFTs, iron studies, renal function test, HIV, hepatitis serologies
  • Differential Diagnosis
    • Pseudoporphyria (from NSAIDs)
    • Porphyria variegata
    • Acute intermittent porphyria
    • Erythropoietic protoporphyria
      • burning pain, erythema, and swelling develops on skin minutes after sun exposure
      • no scarring or blistering
      • protoporphyrins elevated in plasma and RBCs
      • treatment: limit sun exposure; beta-carotene reduces photosensitivity
  • Treatment
    • Avoid exposures (alcohol, estrogen, primidone, other hepatotoxins)
    • Sunscreen use
    • Iron removal by phlebotomy – first line
      • reduces hepatic iron stores – produces remission
      • if phlebotomy not available, deferoxamine
    • Hydroxychloroquine
      • increases excretion of uroporphyrin
  • Prevention & Complications
    • Prevention
      • avoid triggers
  • Prognosis
    • Complete clinical clearing in between 2 months and 2 years after stopping triggers exposures
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Questions (5)

(M2.DM.17.4754) A 36-year-old female presents to her primary care provider for tremor. She reports that she has always had a mild tremor but that she has begun noticing it more since learning to paint. She feels that she has trouble dipping her paintbrush in the paint and making precise strokes on the canvas. She has taken to painting while drinking wine, as she notices that the wine seems to improve her tremor. Her temperature is 97.6°F (36.4°C), blood pressure is 105/61 mmHg, pulse is 58/min, and respirations are 12/min. On exam, she has a high frequency bilateral hand tremor elicited on finger-to-nose testing. Her neurological exam is otherwise unremarkable. The patient is started on a new medication for her symptoms. One week later, she returns with a new complaint of abdominal pain for one day. She reports that she has noticed a darkening of her urine and now has difficulty raising her arms over her head to brush her hair.

This patient was most likely treated with which of the following medications?

QID: 108956
















M 7 C

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(M2.DM.17.4752) A 46-year-old man with a history of hypertension, obesity, and hyperlipidemia presents with complaints of a new skin rash. He was in his usual state of health until 1 week prior when he noted dark urine and a non-pruritic skin rash of his hands. He endorses recent sore throat and rhinorrhea but denies any recent changes in his medications and states that his other medical conditions are well-controlled. He works as a butcher and denies recent travel. The patient denies tobacco use, but does endorse recently increasing his alcohol consumption to 3-4 shots of liquor per night. Figure A shows the findings on skin exam. His temperature is 99.1° F (37.3° C), pulse is 78/min, blood pressure is 135/85 mmHg, respirations are 12/min, and oxygen saturation is 99% on room air. His laboratory results are:

Sodium: 138 mEq/L
Potassium: 4.0 mEq/L
Bicarbonate: 22 mEq/L
Chloride: 105 mEq/L
BUN: 20 mg/dL
Creatinine: 1.0 mg/dL
Glucose: 98 mg/dL

Leukocyte count: 10,900/mm^3
Hemoglobin: 12.4 g/dL
Platelets: 280,000/mm^3

Which of the following is the best treatment for this patient?

QID: 108743







Topical triamcinolone









M 7 D

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(M2.DM.17.4752) A 38-year-old woman with a history of systemic lupus erythematosus, obesity, and hyperlipidemia presents to her primary care physician for evaluation of new bilateral blisters on her hands. She says that she first noticed these blisters shortly after returning from a weekend trip to the beach two weeks prior. She denies any fevers, joint pains, or other skin rash during this period. The patient works in the adult entertainment industry. On examination, there are multiple flaccid blisters of the bilateral dorsal hands with hemorrhagic crusts, mild scarring, and hyperpigmentation. In addition, increased hair growth is noted on the bilateral malar cheeks. Her temperature is 99.1° F (37.3° C), pulse is 95/min, blood pressure is 130/87 mmHg, respirations are 13/min, and oxygen saturation is 98% on room air. Her laboratory results are:

Na+: 140 mEq/L
K+: 4.5 mEq/L
Cl-: 100 mEq/L
HCO3-: 21 mEq/L
BUN: 20 mg/dL
Creatinine: 1.1 mg/dL
Glucose: 104 mg/dL

Leukocyte count: 9,000/mm^3
Hemoglobin: 12.4 g/dL
Platelets: 400,000/mm^3

Anti-nuclear antibody titer 1:320

Which of the following would confirm the diagnosis in this patient?

QID: 108734

Anti dsDNA titers



C-reactive protein



Anti-hemidesmosome titers



Urine porphyrin levels



Tzanck smear



M 6 D

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(M2.DM.15.4678) A 3-year-old boy is brought to his pediatrician by his mother when he developed redness, burning, itching, and exquisite pain all over his arms, lower legs, neck, and face. The mother states that she just recently began taking him to the local playground in the afternoons. She reports that she applied liberal amounts of sunscreen before and during the time outside. She states that they were at the playground for 30 minutes to 1 hour each day for the last 3 days. The patient has experienced prior episodes of redness and pain after being outdoors, but they were relatively minor and resolved within 12 hours. She says his current presentation is much more severe with more exquisite pain than in the past. The patient's vital signs are as follows: T 37.2 C, HR 98, BP 110/62, RR 16, and SpO2 99%. Physical examination reveals edema, erythema, and petechiae over the patient's face, neck, arms, and lower legs. No blistering or scarring of the skin is noted. Which of the following is the best treatment option for this patient's condition?

QID: 107257

Recommend use of a high SPF topical sunscreen



Begin dexamethasone taper



Start therapeutic phlebotomy



Initiate oral beta carotene



Prescribe chloroquine



M 7 E

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(M2.DM.15.72) A 49-year-old male is referred to a dermatologist for evaluation of his lesions, shown in Figure A. Physical exam confirms that these blistering lesions are present on the patient's hands, forearms, face, and lower legs. He denies any abdominal pain but reports that he has been shaving more frequently recently due to increased hair growth on his cheeks. The patient cannot identify any changes or precipitating factors prior to the appearance of these lesions. Further work-up reveals grossly increased urinary porphyrin levels and pink-fluorescence of the urine under a Wood's lamp. Which of the following findings would be expected on biopsy of one of his skin lesions?

QID: 106537

Perivascular edema



Thickened epidermis, absent granular cell layer, and preserved nuclei within stratum corneum



Linear, eosinophilic acid-Schifff positive globules ("Caterpillar bodies")



Neutrophilic infiltrate around capillaries with septal thickening and fibrosis of perivascular fat



Acantholysis and positive direct and indirect immunofluorescence for epidermal IgG deposition



M 6 E

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Evidence (4)
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