Component-resolved diagnostics enables the detection of allergen-specific immunoglobulins E (asIgE) to house dust mite (HDM) proteins, which may help clinicians to face the difficulties in diagnostics of HDM allergy. Currently, almost 40 proteins of Dermatophagoides species, that are able to bind asIgE, have been identified, and this number will certainly increase. The association between sensitisation to particular molecules and allergy symptoms is extensively studied. This investigation enables us to identify HDM molecules that promote respiratory, skin, or food allergies, and it could help us predict the possible course of allergic diseases. The individual repertoire of asIgE improves our understanding of immunological response, which underlies allergy symptoms, and helps to form individual therapeutic regimens. This review provides clinicians with information on Dermatophagoides pteronyssinus proteins available in commercial arrays, and their role in the diagnostics and management of HDM allergy.