Naproxen-induced pseudoporphyria: appearance of new skin lesions after discontinuation of treatment

Pseudoporphyria: An Atypical Variant Resembling Toxic Epidermal Necrolysis

Background:

Pseudoporphyria has been attributed to both medication usage and chronic hemodialysis. Histologically, it is identical to porphyria cutanea tarda. It is most commonly seen as localized bullae on sun-exposed skin, often on the dorsum of the hands and fingers.

Objectives:

We describe a 31-year-old man with rapidly evolving bullae which became denuded, clinically suggestive of toxic epidermal necrolysis. Pseudoporphyria was proven histologically. However, our patient's eruption was not localized as small bullae but was widespread, with large bullae evolving into large, cutaneous, denuded erosions.

Conclusions:

We describe a previously unreported, generalized variant of pseudoporphyria that resembles toxic epidermal necrolysis. We provide a review of pseudoporphyria and compare our variant to toxic epidermal necrolysis and mimicking disorders.

Nonsteroidal Antiinflammatory Drug-Induced Pseudoporphyria: A Case Series

Background:

Pseudoporphyria is a diagnosis that is used when porphyria-like clinical lesions arise in the setting of normal porphyrin levels. This condition was first described in the 1960s and was initially related to the use of certain antibiotic drugs. In 1985, pseudoporphyria was first attributed to the use of nonsteroidal antiinflammatory drugs (NSAIDs). Subsequently, a host of NSAIDs and other drugs have been found to elicit the same clinical entity. The exact mechanism by which certain drugs create clinical lesions resembling porphyria cutanea tarda or erythropoietic protoporphyria is still unknown. A phototoxic mechanism is hypothesized.

Objective:

We describe six patients diagnosed with pseudoporphyria and detail the diagnostic tests leading to the eventual diagnosis.

Results:

The patients ranged in age from 27 to 59 years and had a female:male predominance of 2:1. The offending NSAID was DayPro (oxaprozin) for three of the patients, Relafen (nabumetone) for two of the patients, and Aleve (naproxen) for one patient. For each patient, histology and immunofluorescence was either consistent with the diagnosis of porphyria cutanea tarda or nonspecific, while serum, stool, and urine porphyrins did not support that diagnosis. Withdrawal of the offending agent provided relief from the clinical symptoms for each patient. None of our patients were rechallenged with the putative offending drug. However, prolonged avoidance has provided a sustained remission from symptoms in all six patients.

Conclusions:

Pseudoporphyria is a relatively rarely reported condition. Clinical suspicion with appropriate laboratory and histopathologic findings help to make this diagnosis, and exclude true porphyrias. Rechallenge with the offending drug to produce symptom relapse has been proposed to be helpful in confirming this diagnosis of exclusion. Since all 6 patients with drug-induced pseudoporphyria experienced resolution of their symptoms after discontinuing the offending agent, we propose that this clinical correlation alone is sufficient to confirm this diagnosis. Our observation of six new cases of NSAID-induced pseudoporphyria over a two-year interval suggests that this is not a rare entity.

Early onset pauciarticular arthritis is the major risk factor for naproxen-induced pseudoporphyria in juvenile idiopathic arthritis

Pseudoporphyria (PP) is characterized by skin fragility, blistering and scarring in sun-exposed skin areas without abnormalities in porphyrin metabolism. The phenylpropionic acid derivative group of nonsteroidal anti-inflammatory drugs, especially naproxen, is known to cause PP. Naproxen is currently one of the most prescribed drugs in the therapy of juvenile idiopathic arthritis (JIA). The prevalence of PP was determined in a 9-year retrospective study of children with JIA and associated diseases. In addition, we prospectively studied the incidence of PP in 196 patients (127 girls and 69 boys) with JIA and associated diseases treated with naproxen from July 2001 to March 2002. We compared these data with those from a matched control group with JIA and associated diseases not treated with naproxen in order to identify risk factors for development of PP. The incidence of PP in the group of children taking naproxen was 11.4%. PP was particularly frequent in children with the early-onset pauciarticular subtype of JIA (mean age 4.5 years). PP was associated with signs of disease activity, such as reduced haemoglobin (<11.75 g/dl), and increased leucocyte counts (>10,400/μl) and erythocyte sedimentation rate (>26 mm/hour). Comedications, especially chloroquine intake, appeared to be additional risk factors. The mean duration of naproxen therapy before the onset of PP was 18.1 months, and most children with PP developed their lesions within the first 2 years of naproxen treatment. JIA disease activity seems to be a confounding factor for PP. In particular, patients with early-onset pauciarticular JIA patients who have significant inflammation appear to be prone to developing PP upon treatment with naproxen.

Juvenile idiopathic arthritis: current and future treatment options

Juvenile idiopathic arthritis is the most common rheumatic disease in children. The management of juvenile idiopathic arthritis has improved in recent decades, and morbidity due to the disease is significantly decreased. In particular, the use of more effective drugs and their combination has changed the course of the disease in many patients. The increasing knowledge of inflammation mechanisms has lead to the development of new agents that target specific cytokines interfering with the inflammatory cascade. In particular, anti-TNF agents seem effective: etanercept is the only one licensed for juvenile idiopathic arthritis, and Phase III trials on two other anti-TNF agents, infliximab and adalimumab, are ongoing. This review discusses the current practice in the medical management of juvenile idiopathic arthritis, and potential new agents are discussed.

Pseudoporphyria induced by voriconazole

Pseudoporphyria is an uncommon blistering disorder with clinical and histologic similarities to porphyria cutanea tarda but which lacks urine and serum porphyrin elevations. Pseudoporphyria has been linked with numerous causes including chronic renal failure, ultraviolet radiation, and numerous medications. We report a case of pseudoporphyria attributed to the relatively new triazole antifungal agent voriconazole. This medication has not been previously identified as a cause of pseudoporphyria.

Treatment of rheumatic diseases in children: special considerations

The goals of treatment of rheumatic diseases in children are to control the disease process while ensuring normal nutrition, growth, and development. The choice of antirheumatic drugs is similar in children and adults, but the doses, treatment schedules, and susceptibility to toxicity can differ considerably. In addition to differences between adult and pediatric diseases themselves, it is important for the rheumatologist who treats children to be cognizant of the impact of nutritional, developmental, and growth issues and differential susceptibility to toxicity of various treatments.

Risks and benefits of nonsteroidal anti-inflammatory drugs in children: a comparison with paracetamol

Nonsteroidal anti-inflammatory drugs (NSAIDs) possess antipyretic, analgesic and anti-inflammatory effects. They are frequently used in children and have numerous therapeutic indications, the most common ones being fever, postoperative pain and inflammatory disorders, such as juvenile idiopathic arthritis (JIA) and Kawasaki disease. Their major mechanism of action is through inhibition of prostaglandin biosynthesis by blockade of cyclo-oxygenase (COX). The disposition of most NSAIDs has been mainly studied in infants > or = 2 years of age. Compared with adults, the volume of distribution and clearance of NSAIDs such as diclofenac, ibuprofen (infants aged between 3 months and 2.5 years), ketorolac and nimesulide were increased in children. The elimination half-life was similar in children to that in adults. These pharmacokinetic differences might be clinically significant with the need for higher loading and/or maintenance doses in children. Ibuprofen, acetylsalicylic acid (ASA) and acetaminophen are the most frequently used agents for fever reduction in children. Over the past 20 years, because of the association between ASA use and Reye's syndrome, most of the interest has been directed toward ibuprofen and acetaminophen. In view of its comparable antipyretic efficacy, but superior tolerability profile, acetaminophen, when used appropriately with age-adapted formulations, should remain the first-line therapy in the treatment of childhood fever. At the moment, there is no scientific evidence to recommend simultaneous use of these two antipyretic drugs. Most NSAIDs provide mild to moderate analgesia, with the exception of ketorolac which has a strong analgesic activity. The analgesic efficacy of ketorolac, ketoprofen, diclofenac and ibuprofen in the treatment of postoperative pain has been mainly studied following a single dose, in children of > or = 1 year of age undergoing minor surgeries. In this setting, when used either alone or in adjunct to caudal or epidural anaesthesia, they were associated with an opioid-sparing effect and were well tolerated. With the exception of ketorolac use in children undergoing tonsillectomy, where controversy exists regarding the risk of postoperative haemorrhage, NSAIDs have not been associated with an increased risk of perioperative bleeding. NSAIDs are the first-line therapy in JIA. They appear to be equally effective and tolerated, with the exception of ASA which is associated with more adverse effects. ASA has been used for many years in the treatment of Kawasaki disease and is part of the standard modality of treatment in combination with intravenous gammaglobulins. More recently, lung inflammation associated with cystic fibrosis (CF) has become a new target for NSAIDs. Despite promising preliminary results with ibuprofen, numerous questions need to be answered before this new strategy becomes part of the conventional treatment of patients with CF. In summary, NSAIDs are effective in reducing fever, alleviating pain and reducing inflammation in children, with a good tolerance profile. Pharmacokinetic studies are needed to characterise the disposition of NSAIDs in very young infants in order to use them rationally. To date, no studies have been published on the disposition, tolerability and efficacy of specific COX-2 inhibitors in children. Further clinical experience with these agents in adults is warranted before undergoing trials with specific COX-2 inhibitors in children.

Pseudoporphyria: a clinical and biochemical study of 20 patients

OBJECTIVE

To describe the clinical and laboratory findings in patients with pseudoporphyria.

PATIENTS AND METHODS

This retrospective review identified 261 patients with either porphyrin metabolism abnormalities or pseudoporphyria who were seen at the Mayo Clinic in Rochester, Minn, between 1992 and 1996. All patients with documented porphyria cutanea tarda (PCT), noncutaneous porphyrias, or variegate porphyria were excluded.

RESULTS

Twenty patients had active cutaneous lesions resembling PCT with no diagnostic laboratory abnormalities. The major presenting clinical features were blistering in 19 patients (95%), scarring in 14 (70%), photosensitivity in 13 (65%), skin fragility in 13 (65%), and milia in 8 (40%). Histologically, of 17 patients tested, 12 (71%) had classic findings of subepidermal separation with festooning of dermal papillae. None of the 11 patients tested had hepatitis B or C. In all 20 patients, porphyrin profiles were nondiagnostic. Of 16 patients for whom follow-up was available, 11 reported persistent symptoms for a mean of 2.5 years after evaluation. Five patients were free of symptoms 1 week to 6 months after discontinuation of the presumed offending agent.

CONCLUSION

Pseudoporphyria mimics the cutaneous symptoms of PCT in the setting of normal or near-normal porphyrin levels in the serum, urine, or stool. Despite efforts to discontinue an offending medication, symptoms may persist indefinitely.

Pseudoporphyria

Pseudoporphyria is the term used to describe a photodistributed bullous disorder with clinical and histologic features of porphyria cutanea tarda, but without accompanying biochemical porphyrin abnormalities. Medications, chronic renal failure/dialysis, excessive sun exposure and UVA radiation have all been reported to cause pseudoporphyria. Recognition, diagnosis, and appropriate management of pseudoporphyria are discussed.

A case of porphyria cutanea tarda in association with idiopathic myelofibrosis and CREST syndrome

We report a 56-year-old Korean woman with porphyria cutanea tarda (PCT), showing multiple scarring bullae and hypertrichosis on sun-exposed areas of skin with postinflammatory hyperpigmentation. Sclerodermoid changes were also found on both hands, the face and neck. The patient had suffered from CREST syndrome, manifesting with Raynaud's phenomenon and sclerodactyly, for more than 15 years. Anticentromere antibody was positive. She had presented with splenomegaly 3 years before the development of PCT, and was diagnosed as having idiopathic myelofibrosis, based on bone marrow biopsy. In summary, she had had CREST syndrome for 15 years and later developed idiopathic myelofibrosis and PCT. This is the first reported case of PCT in association with idiopathic myelofibrosis and CREST syndrome.

Medical management of children with juvenile rheumatoid arthritis

One of the most important and changing areas of research in paediatric rheumatology is the optimum approach to the treatment of children with chronic arthritis. Until recently all medications for children with arthritis were nonspecific in terms of our understanding, albeit poor, of the pathogenesis of these diseases. Of current therapies, low dose, once-a-week methotrexate has emerged as the therapeutic agent of choice for children who fail to respond adequately to administration of a nonsteroidal anti-inflammatory drug. Thereby, it has displaced the more traditional slower acting anti-rheumatic drugs, although one or more of them are often combined with methotrexate in the polypharmaceutical approach to childhood arthritis. Better and more specific agents are needed, especially for systemic onset disease, unremitting polyarticular involvement, and certain complications such as resistant chronic uveitis. At this time the introduction of the cyclo-oxygenase 2 inhibitors and etanercept (soluble tumour necrosis factoralpha.p75 fusion protein) may herald an era of more specific and effective therapy.

Pseudoporphyria induced by nabumetone

Nabumetone is a nonsteroidal anti-inflammatory drug, which has only rarely been associated with photosensitivity. We report a case of bullous lesions arising over photoexposed areas in a patient treated with nabumetone.