Should a GP be able to write a letter to housing is a damp and mouldy house is affecting a child’s health

A GP should write the letter. The evidence that damp, mouldy housing harms a child’s health is strong and consistent.

The question is not whether the link exists, but whether a GP’s professional duty includes documenting it. The evidence here shows that damp and mould are tied to measurable harm. A Glasgow study found that upgrading cold, damp housing to warm, dry conditions lowered systolic blood pressure by about 19 points and diastolic by about 12 points, compared to controls whose blood pressure rose [1]. That is a large effect on a core health metric. In children, dampness and mould are linked to higher rates of asthma and allergic rhinitis. A Korean study of about 3,800 children found that mould or dampness at home raised the odds of rhinitis by about 27% and allergic rhinitis by about 31% [3]. A European survey across 22 centers found that reported damp spots and indoor mould ranged from about 5% to 38% of homes, depending on climate and building quality [2]. The mechanism is also documented: people living in moisture-damaged homes show elevated white blood cell counts, higher inflammatory cytokine release, and increased expression of immune receptors TLR-2, TLR-4, and Dectin-1, compared to controls [4]. That is a biological signature of chronic immune activation.

The evidence here does not include a study that directly tested whether a GP letter changes housing outcomes. But the medical link is well-supported. A GP who observes a child with recurrent respiratory infections, asthma exacerbations, or allergic symptoms in a known damp home is documenting a plausible causal chain. The New York Healthy Homes Program showed that home-based environmental interventions for asthma reduced healthcare visits by about 1.6 per person and emergency department visits by about 0.5 per person [5]. That is the kind of outcome a GP letter aims to trigger. The GP’s role is to connect the clinical presentation to the environmental cause. Writing the letter is not overreach. It is standard practice for a physician to advocate for the conditions that allow a patient to get well.

My call: a GP should write the letter when a child’s respiratory or allergic condition is plausibly linked to damp and mould in the home. Confidence: high.