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Abstract

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 earlyonset pauciarticular JIA patients who have significant inflammation appear to be prone to developing PP upon treatment with naproxen.

Genetic influences on the dynamics of pain and affect in fibromyalgia.

“…The frequencies of the val 158 met genotypes in COMT have been reported as follows in a Spanish-origin FM population: [12% ( val / val ), 51% ( val / met ), 37% ( met / met ); Vargas-Alarcon et al, 2007]. Due to the functionally intermediate action of the heterozygous val/met genotype, gene effects were expected to be largest for individuals with homozygous genotypes.…”

Pseudoporphyria induced by hemodialysis

“…Schäd et al . [ 16 ] and Werth [ 17 ] estimated pseudoporphyria risk factors in children with juvenile arthritis exposed to long-term treatment with naproxen. It has been shown that pseudoporphyria more frequently appears in the group with higher leucocytosis, WBR, lower level of haemoglobin and in the group receiving anti-malaria drugs (possible treatment use in pseudoporphyria!).…”

An overview of the cutaneous porphyrias

“…Certain chemicals can induce a porphyria, such as hexachlorobenzene, a pesticide that caused an epidemic of a porphyria, with cutaneous features akin to PCT, in Turkey 4 . The term pseudoporphyria is usually used when porphyria is excluded as the cause of a PCT-like presentation, but the term is also used to encompass some features more similar to EPP, such as in children taking naproxen 5 , and is usually a drug-induced adverse effect (commonly caused by a non-steroidal anti-inflammatory drug and often naproxen), although it has also been reported with high cumulative exposure to sunbed radiation in the absence of a recognised drug trigger. In kidney failure, a PCT-like presentation may not be due to an abnormality in porphyrin–haem metabolism or to a drug but to raised porphyrins due to failure to excrete them.…”