Allergy, autoimmunity, and cytokine storm can be placed on two independent axes. The first axis is targeting: is the response aimed at a harmless antigen (allergy), at a self antigen (autoimmunity), or at a genuine antigen that is being handled with excessive force (cytokine storm)? The second axis is regulation: has the response lost its ceiling, so that it keeps growing after the trigger should have been cleared?
Allergy is misdirection without loss of amplification control. The IgE-mast cell pathway is a normal, self-limiting effector module; the error is that it was built against a harmless allergen. Autoimmunity is also misdirection, but the target is self tissue, and the failure sits in tolerance checkpoints: central tolerance let a self-reactive clone escape, or peripheral tolerance failed to restrain it. Cytokine storm is different in kind. The trigger may be a real pathogen, and the targeting is not wrong; what fails is the negative regulation that normally contracts a response. Cytokine output becomes its own input, so the loop grows instead of resolving.
This gives a compact diagnostic rule. Ask first whether the target is harmless, self, or genuinely dangerous. Then ask whether the response is bounded or self-amplifying. Allergy and autoimmunity share the first failure mode; cytokine storm is the second. A condition can combine both, but separating the axes keeps the mechanism clear.