Recurrent abdominal pain in children does toxocariasis play a role?

ABSTRACT

Recurrent abdominal pain [RAP] of unexplained etiology is a relatively common pediatric problem. It is often referred to as functional abdominal pain with only 5-10% of the affected children have organic causes for their pains. Toxocariasis, a helminthic zoonosis, causes a spectrum of diseases in man two major syndromes; visceral larva migrans [VLM], Ocular larva migrans [OLM] and a third more common condition, covert toxocariasis in which positive toxocara serology [both anti-toxocara excretory-secretory IgG and IgE] are associated with a number of systemic and localized symptoms and signs; notably recurrent abdominal pain. It has been implicated as a cause of RAP which might be otherwise interpreted as an idiopathic. Aim of this study is to assess the role of toxocariasis as a causative agent of unexplained recurrent abdominal pain in our children based on clinical, serological and therapeutic criteria. One hundred fifty children suffering from RAP were included in our prospective study. After detailed history, thorough clinical examination and relevant investigations, patients were divided into two groups the first with organic RAP and the second with unexplained RAP. Patients in the second group were subjected to complete blood count, eosinophilic count, urine and stool analysis, ELISA serotesting for anti-Toxocara excretory- secretory [TES] IgG and IgE and were followed-up for three months. Seropositive [IgG] patients were treated with Albendazole and re-tested for specific antibodies at the end of our study. Out of 150 children with RAP, 26.6% [40 patients] showed definite organic causes with intestinal parasites, particularly Giardia lamblia, represented the most common etiology. Among the remaining 73.4% [110 patients] who were addressed as unexplained RAP, 21.8% [24 patients] were anti [TES] IgG positive. Almost half of them [13 patients] were seropositive for anti [TES] IgE also [covert toxocariasis]. Unexplained RAP was the sole presentation in 61% [8/13] of them and high blood esinophils [>5% of TBL] was a common finding 77% [10/13]. Anti [TES] IgE was positive in 92% of chemoresponsive patients and was negative in all non-respenders. Post treatment mean of anti [TES] IgE showed significant decrease [P <0.05] when compared to pre-treatment level [45 +/- 9.8 Vsl90 +/- 13.3] while no difference can be proved regarding anti [TES] IgG [1.22 +/- 0.35 Vs 1.28 +/- 0.32]. Covert Toxocariasis may be a hidden cause of unexplained RAP in children and should be enlisted in its differential diagnosis particularly if associated with eosinophilia. ELISA quantitative assay of anti TES IgE, not only provide a specific diagnostic indicator for covert Toxocariasis but is a useful tool in monitoring drug therapy as well