Agency for Toxic Substances and Disease Registry
Case Studies in Environmental Medicine (CSEM) 

Environmental Triggers of Asthma
Case Study (Continued)

Case Study (Continued)

A review of the exposure history for the 12-year-old reveals that:

• the family has a long-haired cat that stays in the house,
• the patient develops nasal congestion and chest tightness when playing with the pet,
• the central heating furnace filters have not been cleaned in the last year,
• wall-to-wall carpet is present throughout the house,
• the home has a wood-burning fireplace, which is occasionally used,
• the shower areas of the bathrooms have some mold, and
• both parents smoke cigarettes indoors, but do not smoke in the children’s rooms.

In addition, the patient’s mother states that:

• she vacuums regularly,
• she has not seen any insects in the house, and
• the basement is not damp.

The patient with asthma symptoms underwent peak flow testing in your office. The results demonstrated a 24% increase in PEFR after administration of a short-acting B₂-agonist bronchodilator. At the end of the clinic appointment, the patient is diagnosed with mild persistent asthma. She is given anti-inflammatory therapy consisting of a corticosteroid metered-dose inhaler (MDI) for daily use and a short-acting B₂-agonist MDI for symptomatic relief. The patient is instructed on use of the MDIs with the spacer. The patient uses the spacer in front of you to demonstrate that she understands its proper use. You explain to the patient that it might take 7 days or more for the corticosteroid inhaler to be effective. You also explain that the goal is to control the asthma with the corticosteroid inhaler and decrease use of the short-acting B₂-agonist for rare breakthrough of acute asthma symptoms. She is scheduled for a return visit in 2 to 3 weeks.

You tell the mother that both parents should stop smoking or, at a minimum, they should not smoke in the house or the car. In addition, the furnace filter should be replaced or cleaned on a regular basis. The cat should not be permitted indoors, and wall-to-wall carpeting should be removed from the patient’s bedroom (and preferably the whole house if feasible). Mattresses and pillows should be encased in sealed plastic covers and all bedding materials washed in hot water (>130°F [>55°C]) to kill dust mites. Water heaters in homes with young children are frequently set at or below 120°F (50°C) to avoid scalding, so you suggest that the mother turn the water heater up for short periods to provide the necessary water temperature for washing bedding and area rugs.

Case Study Follow-Up

A few weeks later, the father brings his daughter in for her follow-up assessment. The child’s cough has subsided and she is able to sleep through the night. The child has been using the short-acting B₂-agonist and corticosteroid inhaler as directed. For the last week, she has not required additional use of the short-acting B₂-agonist. The father relates that his daughter has been more active lately and plays soccer without episodes of shortness of breath. Auscultation of the lungs reveals that both fields are clear without wheezes. You decide to maintain the current medication treatment regimen. The father has an audible wheeze and an intermittent cough. He is wearing his factory work clothes and you smell a strong chemical odor coming from him. You reiterate that both parents should stop smoking. At a minimum, they should not smoke in the house or the car.

Progress Check