Types of hypersensitivity
There are four types of allergic (or hypersensitivity) response of differing intensities and speed of response. In the most severe cases this can result in death.
There are two types of hypersensitivity that relate to hair dye.
| Characteristic | Type I | Type IV |
|---|---|---|
| Antibody | IgE | None |
| Antigen | Exogenous | Cellular |
| Response time | 15-30 mins | 48-72 hours |
| Appearance | Weal and flare | Erythema and induration |
| Histology | Basophils and eosinophils | Monocytes and complement |
| Transfer with | Antibody | T-cells |
| Examples | Hay fever, asthma | TB Test, poison ivy |