What condition should a specialist suspect for a child with a sweat chloride level of 88 mEq/L?

A sweat chloride level of 88 mEq/L is significantly elevated and is indicative of cystic fibrosis. This condition is characterized by defective chloride channels in epithelial cells, leading to the accumulation of thick, sticky mucus in various organs, particularly the lungs and pancreas. An elevated sweat chloride concentration is a key diagnostic criterion for cystic fibrosis, with levels greater than 60 mEq/L strongly suggestive of the disease.

In the context of cystic fibrosis, the elevated sweat chloride reflects an abnormality in sweat gland function, where chloride and sodium are not reabsorbed properly, leading to increased concentrations in sweat. The specific threshold value used in making a diagnosis can sometimes vary slightly among different guidelines, but a level of 88 mEq/L clearly supports the diagnosis.

Other conditions such as diabetes mellitus, pleural effusion, and asthma do not typically present with elevated sweat chloride levels as a diagnostic feature. While these conditions can affect respiratory function and overall health in children, they do not share the hallmark of atypical sweat chloride concentrations seen in cystic fibrosis. Thus, the correct suspicion in this scenario is cystic fibrosis, making it the most appropriate answer to the question posed.