Context

This codelist was developed within the Pharmacy First project as a control condition for analyses related to infected insect bites. Allergic conjunctivitis was selected as a comparator condition because it is generally unrelated to skin and soft tissue infections and is managed through community pharmacy and primary care pathways. The codelist is intended for use in observational analyses evaluating prescribing patterns within Pharmacy First pathways.

Inclusion/exclusion criteria

The codelist includes SNOMED CT (UK Clinical Edition) codes representing allergic conjunctivitis and closely related allergic ocular inflammatory conditions likely to present in primary care or community pharmacy settings. Terms capturing seasonal, perennial, acute or unspecified allergic conjunctivitis were considered for inclusion where clinically relevant.

Borderline cases

Codes describing unspecified conjunctivitis were reviewed carefully because they may represent infective rather than allergic disease. These were excluded unless the terminology explicitly indicated an allergic aetiology. Conditions overlapping with atopic eye disease were included only when allergic conjunctival involvement was clearly specified.

Sensitivity vs specificity

The codelist was designed to prioritise specificity over sensitivity. The intention was to identify consultations likely to represent allergic conjunctivitis while minimising inclusion of infective eye conditions that could overlap clinically with Pharmacy First infectious pathways.

Additional information

This codelist was created using SNOMED CT UK Clinical Edition release 42.0.0 and is intended evaluation purposes within the Pharmacy First project. Clinical review was undertaken to ensure consistency with primary care coding practices and the intended comparator role for infected insect bite analyses.