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Field cancerization was first described in 1953 as histologically altered mucosa surrounding tumours removed from the upper gastro-intestinal tract. Over the years the definition has changed to include an area which is clinically occult but has multifocal preneoplastic changes, showing genetic mutations and which precedes the development of second primary tumours and local recurrences. Field cancerization has been described in the oropharynx, oesophagus, stomach, lung, colon, anus, cervix, bladder and skin. Various molecular techniques have been developed to look for genetic mutations and clonality in areas of field change. These studies have highlighted the need for early detection and treatment in order to prevent the development of tumours and local recurrences. In this article we examine the concept of field cancerization and treatments available to manage field change.

Patch test was evaluated for the identification of causative agent in cutaneous eruptions due to antiepileptics. Patch tests were carried out in twenty patients and ten controls with carbamazepine, phenytoin sodium, phenobarbitone and sodium valproate. Sodium valproate was found tobe irritant in 1 and 5% concentration and further dilution is recommended for patch testing. Patch test was positive in 14 (70%) patients and in 7 with suspected drug alone, and remaining 7 were positive with more than one antiepileptic drug. We recommended patch test for identification of causative drug in rashes due to antiepileptics.

Clinical profile of 105 patients with cutaneous drug eruption due to antiepileptic drugs was studied between 1992-1996. Maculopapular rash was the most common presentation though significant number of patients (29.5%) had serious rashes like Stevens Johnson syndrome (SJS) and toxic epidermal necrosis (TEN). Phenytoin and carbamazepine were the two commonly implicated drugs. Significant number of our patients had liver and kidney involvement (47.34 and 21.04%, respectively). The overall prevalence of drug rash with antiepileptics in a review of 240 cases was found to be 2.5%. Patch testing with antiepileptic drugs done in 20 patients gave 60% positive results with the suspected drug. Thus patch test is a useful tool in confirming the diagnosis of drug rashes and warrants further studies.

A 7-year-old boy had several episodes of severe anemia, requiring hospitalizations and blood transfusions. Skin hemangiomas characteristic of blue rubber bleb nevus syndrome were present since infancy, but were not recognized as being indicative of simultaneous existence of bowel hemangiomas, resulting in a delay of several years before an accurate diagnosis could be made.