A nurse is caring for a toddler who has acute laryngotracheobronchitis and has been placed in a cool mist tent. Which of the following findings indicates that the treatment has been effective?

Choice A reason: This test measures the level of antibodies that the body produces against the streptolysin O enzyme, which is produced by some strains of streptococcal bacteria. A high level of ASO titer indicates that the child had a recent streptococcal infection, which may trigger rheumatic fever in some cases.

Choice B reason: This test does not directly indicate if the child has rheumatic fever. Rheumatic fever is a complication of untreated or inadequately treated streptococcal infection, which causes inflammation of the heart, joints, skin, and brain. The diagnosis of rheumatic fever is based on clinical criteria, such as the presence of carditis, polyarthritis, chorea, erythema marginatum, or subcutaneous nodules.

Choice C reason: This test does not confirm if the child has immunity to streptococcal bacteria. Immunity is the ability of the body to resist or fight off an infection. A high level of ASO titer does not mean that the child is immune to streptococcal bacteria, but rather that the child was exposed to them recently.

Choice D reason: This test does not indicate if the child has a therapeutic blood level of an aminoglycoside. Aminoglycosides are a class of antibiotics that are used to treat serious bacterial infections, such as endocarditis or septicemia. The blood level of an aminoglycoside is measured by a different test, called a peak and trough level, which determines the effectiveness and safety of the drug.

Choice A reason: Herpes simplex is a viral infection that causes painful blisters or ulcers in the mouth or on the lips. It does not cause a white, milky plaque that does not come off with rubbing.

Choice B reason: Dermatitis is a skin inflammation that causes redness, itching, and scaling. It does not affect the mouth or cause a white, milky plaque that does not come off with rubbing.

Choice C reason: Squamous cell carcinoma is a type of skin cancer that develops from the squamous cells that line the mouth and other parts of the body. It causes a hard, irregular, or ulcerated growth that may bleed or become infected. It does not cause a white, milky plaque that does not come off with rubbing.

Choice D reason: Candidiasis, also known as oral thrush, is a fungal infection that causes a white, milky plaque that coats the tongue, cheeks, and roof of the mouth. It can be scraped off, but may leave a red, sore, or bleeding surface. It is more common in people who have a weakened immune system, such as those who take antibiotics, immunosuppressants, or corticosteroids. It can also be triggered by smoking, dry mouth, or poor oral hygiene.