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Red urine and photosensitive skin rash: not only was our patient's urine red, but his teeth had a reddish hue, as well.

A 40-year-old Muslim man, born of consanguineous parentage, came into our clinic and told us that since infancy, he'd had recurrent blistering and skin fragility in light-exposed areas. His condition had been getting worse over the years. Also since childhood, he'd been passing "blood" in his urine.

On examination, we noticed scarring and mottled hypo- and hyperpigmentadon of his face, dorsum of his hands, and other sun-exposed areas. He also had excessive hair growth on his face and extremities, and multiple milia on the pinnae and dorsum of his hands.

[FIGURE 1 OMITTED]

In addition, he had numerous small ulcerations on the dorsum of his hands; his terminal phalanges were mutilated, with beaking of the nails (FIGURE 1). His teeth had a reddish hue and his urine was, indeed, blood red.

The systemic examination was unremarkable and besides the red color, routine urine examination revealed no abnormality. A Wood's lamp examination showed pink fluorescence of his teeth and urine.

* What is your diagnosis?

* Diagnosis: Congenital erythropoietic porphyria

Erythropoietic porphyria (EP) is a rare, autosomal recessive inborn error of metabolism, primarily involving bone marrow heme synthesis. EP affects diverse populations without any racial or gender predilection, and typically involves infants and young children, though several adult-onset cases have been reported. (1,2)

EP patients typically have a history of early onset photosensitive blistering skin rash, erythrodontia (reddish coloration of teeth), and red urine (FIGURE 2). Hypertrichosis, scarring, and milia formation are other important clinical findings.

In EP, a deficient activity of the enzyme uroporphyrinogen III synthase in erythrocyte precursor cells results in overproduction of isomer I porphyrinogens that cannot be used to form heme. These isomer I porphyrinogens are oxidized to their corresponding porphyrins, which are water-soluble photosensitizers.

Release of these porphyrins from the maturing erythrocytes into the plasma and their subsequent renal excretion makes urine turn a port-wine color. The interaction between light radiation and excess porphyrins in the skin results in photooxidative damage. The photoactive porphyrin molecules also cause bright pink fluorescence of urine, teeth, and bones under ultraviolet light.

The differential includes erythropoietic protoporphyria

When considering a diagnosis of EP, you'll need to rule out erythropoietic protoporphyria, porphyria cutanea tarda, variegate porphyria, xeroderma pigmentosum, and pseudoporphyria. The natural history of EP lesions, clinical examination, and lab work will help you make the diagnosis.

Erythropoietic protoporphyria usually occurs in childhood. The degree of photosensitivity is variable and patients will usually come in with erythema, urticarial plaques, and, rarely, blisters. Skin thickening and scarring can occur. Urine, however, is normal in color. (1)

[FIGURE 2 OMITTED]

Porphyria cutanea tarda usually occurs in the third or fourth decade and rarely before puberty. Photosensitive blistering along with scarring, milia formation, dyspigmentation, and hypertrichosis are other important features, but erythrodontia is absent)

Variegate porphyria is associated with prominent neuro-visceral symptoms, which help differentiate it from EP. (3)

Xeroderma pigmentosum is characterized by early onset photosensitivity, photophobia, and multiple freckles. Secondary malignant changes occur universally. Urine color is normal in these patients. (3)

Pseudoporphyria patients usually have cutaneous manifestations of porphyria cutanea tarda without any demonstrable porphyrin abnormalities. In addition, there is usually a history of drug intake and maintenance hemodialysis for chronic renal failure. (1)

History and lab work clinch the diagnosis

An EP diagnosis can be made on the basis of a history of an early onset photosensitive blistering skin rash, erythrodontia, and red fluorescent urine. Porphyrin analyses are also important. The combination of elevated urinary and erythrocyte uroporphyrin I levels is specific for EP. Red porphyrin fluorescence in intact erythrocytes and erythroid precursor cells can be observed in smears of bone marrow specimens illuminated by violet or blue light against a dark field. (2)

Histopathological features are nonspecific because similar changes can be found in all types of porphyria. Papillary dermal tips often protrude into the blister cavity due to the increased rigidity of the hyalinized vessel walls. The so-called "caterpillar bodies," which are eosinophilic linear structures in the roofs of bullae composed of basement membrane material, have been found in blisters of several forms of porphyria. (2)

In our patient, an X-ray of his hand showed acroosteolysis, and a routine hemogram was suggestive of hemolytic anemia. His urinary porphyrin concentration--mostly uroporphyrin I--was greatly increased, confirming the diagnosis. Histopathology showed subepidermal splits with sparse lymphocytic infiltrate around superficial vasculature, which had markedly thickened walls.

Photoprotection is a cornerstone of treatment

Patients with EP need to wear sun-protective clothing and hats, as well as sunscreen, when outside. Sunscreens containing physical light-reflective agents such as zinc oxide or titanium dioxide provide good protection. (4)

Oral beta-carotene (120-180 mg daily) (1) for photoprotection has been used with variable success. Oral activated charcoal and cholestyramine are used to retard and prevent reabsorption of endogenous porphyrins.

Other useful treatment options include repeated transfusions of packed red blood cells and bone marrow transplantation. (3)

Patients with EP should be advised to avoid any form of mechanical trauma so as to lessen ulcerations, and thus, scarring.

A good outcome for our patient

Despite the limited treatment options that are currently available, the prognosis for EP patients is not gloomy. Most patients with EP survive into adulthood, with a life expectancy of 40 to 60 years. (2)

We advised our patient to avoid sun exposure and to take oral beta-carotene. Apart from occasional photosensitive blistering, he is now enjoying good health.

Disclosure

The authors reported no potential conflict of interest relevant to this article.

References

(1.) Bickers DR, Frank J. The porphyrias. In: Freedberg IM, Eisen AZ, Wolff K, et al, eds. Fitzpatrick's Dermatology in General Medicine. 6th ed. New York: McGraw-Hill; 2003:1435-1466.

(2.) Hebel JL, Poh-Fitzpatrick MB. Erythropoietic porphyria, e-Medicine. Updated January 12, 2009. Available at: http://emedicine.medscape.com/article/1103274-overview. Accessed February 27, 2009.

(3.) James WD, Berger TG, Elston DM., eds. Andrew's diseases of the skin. 10th ed. Canada: Saunders Elsevier; 2006.

(4.) Bari A. Congenital erythropoietic porphyria in three siblings. Indian d Dermatol Venereol Leprol. 2007;73:340-342.

Sudip Kumar Ghosh, MD, DNB, DDERMAT

Debabrata Bandyopadhyay, MD

Department of Dermatology, Venereology, and Leprosy, R.G. Kar Medical College,

West Bengal, India

dr_skghosh@yahoo.co.in

Susmit Haldar, MD, DNB

Calcutta Skin Institute, West Bengal, India

EDITOR

Richard R Usatine, MD

University of Texas Health

Science Center at San Antonio

Correspondence

Sudip Kumar Ghosh, MD, Vill & P.O.-Rajballavpur (Via Maslandpur), District 24 Parganas (North), West Bengal, India 743289; dr_skghosh@yahoo.co.in
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Title Annotation:PHOTO ROUNDS
Author:Ghosh, Sudip Kumar; Bandyopadhyay, Debabrata; Haldar, Susmit
Publication:Journal of Family Practice
Geographic Code:1USA
Date:Apr 1, 2009
Words:1071
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