Depends on the person's allergy.
I knew of someone who was allergic to the 1980's Persil "New System" powder.
An aunt is allergic to any Procter & Gamble detergent (Ariel, Bold, Daz, Fairy) yet is fine with Persil Biological powder.
An ex of mine could only use Persil Non-Bio. Anything else caused severe eczema.
Typically four or five enzymes in Ariel and Persil, (e.g.; amylase, protease, cellulase, glycosidase, lipase, mannanase).
Typically one or two enzymes in UK Surf and Daz, (protease, amylase).
Reformulations take place quite regularly, so enzymes are added, removed or swapped as the manufacturers see fit.
Part of the allergy thing is the extremely strong fragrance used in most of the detergents on the market today.