Nongenital warts are generally harmless, self-limiting and often recover spontaneously; existing treatments usually require months to induce healing and recurrence is common [1]. Topical salicylic acid is widely use in wart removal; however, although generally well tolerated, it may elicit both local and systemic manifestations [2, 3]. Serious reactions to topical salicylate preparations so far reported are usually ascribed to percutaneous absorption of excessive amounts of salicylate ointment [3]. Here we present an unusual case of serious systemic illness arising in a child after the application of salicylic acid patches for a plantar wart. Parents sought advice for their 9-year-old son, after he had been complaining for 2 weeks of abdominal pain, nausea, constipation, increasing weakness and general illness. The abdominal pain started 2 days after beginning daily topical application of 15% salicylic acid patches (3.75 mg, 6 mm) for a plantar wart, and it was followed by the other symptoms a few days later. Familiarity with atopy, personal history of previous atopic dermatitis, food allergy, asthmatic bronchitis and cutaneous eruptions following clarithromycin administration were reported by his parents. Laboratory data (haemocrome, creatininaemia, glycaemia, transaminases, amylase, antitransglutaminase IgA, anti-Helicobacter pylori IgG) were normal except for IgE levels (53 kU l−1, normal values < 25 kU l−1). Stool samples were negative for common gastroenteritis agents (Salmonella, Shigella, Campylobacter, Rotavirus, Adenovirus, common parasites) and for occult blood. Instrumental examinations (abdominal ecosonography and X-ray) showed delayed gastric empting and coprostasis. After 3 weeks of unsuccessful therapy with domperidone and fleet enemas, the general condition significantly worsened with the appearance of mildly impaired mental performance. Symptoms considerably improved only a few days after the suspension of salicylate patch application (1 month after the beginning of treatment) and worsened again a couple of days later, when a new patch was applied for a relapsing wart. Definitive cessation of the topical treatment was followed by progressive improvement of the patient's condition and symptoms completely disappeared within 2 weeks. To the best of our knowledge, this is the first report of such a systemic clinical picture occurring after the application of salicylic acid-containing patches. Although the clinical picture described is complex and unusual, the close temporal relationship between patch application and occurrence of symptoms, together with positive dechallenge and rechallenge and with the exclusion of any other alternative explanation (e.g. gastroenteritis, coeliac disease, other drugs), strongly supports topical preparation as the causative agent of the adverse reaction. Salicylates can be absorbed percutaneously, and wounded skin can increase local and systemic concentrations [3]. In this case, however, the reaction may not necessarily have been triggered by systemic exposure, also in view of the very low amount of salicylic acid contained (3.75 mg) and the small diameter (6 mm) of the patches. Even though nausea and epigastric pain in our patient may be consistent with salicylism, only routine examinations were performed in view of the medium clinical severity of symptoms. Glycaemia was normal, whereas electrolyte balance, acid-base status, and serum salicylate levels were not evaluated. Nonetheless, other common features of salicylism, such as sweating, tinnitus, blurring of vision and tachypnoea, were not observed, therefore, systemic toxicity was deemed unlikely. Salicylic acid may also evoke pseudoallergic (‘salicylate intolerance’) reactions, which are non-immunological reactions related to overproduction of leukotriene metabolites and impaired prostaglandin (PG) synthesis due to cyclooxygenase-1 inhibition [4]. Interestingly, clinical evidence indicates that both food allergy and its non-immunological form, food intolerance, may be associated with abdominal pain, constipation and coprostasis [5, 6], the main symptoms observed in our patient. Moreover, non steroidal anti-inflammatory drug (NSAID) use may be a risk factor for chronic constipation, probably due to the inhibition of PG synthesis [7]. Thus, also in view of our patient's atopic profile, which is considered a risk factor for NSAID hypersensitivity [8], we interpreted the clinical picture as a pseudoallergic reaction to topical salycilate involving the gastroenteric tract. The parents were advised not to use any salicylic acid preparation for their son, either topical or systemic, and, in case of need, to choose paracetamol as a safe alternative, since it had been used previously in this subject and was well tolerated. In conclusion, considering the usually benign nature as well as the high rates of spontaneous remission, the risks and benefits of topical salicylate in the treatment of nongenital warts should always be carefully evaluated.