Cyclic peptides and analogs useful to treat allergies

A cyclic compound composed of from 4 to 10 residues comprising a contiguous sequence of residues selected from structures (Ia)-(Ie):

• X26˜X25˜X21˜X25;
• (Ia) X22˜X24˜X27˜X29;
• (Ib) X21˜X22˜X24˜X29;
• (Ic) X22˜X21˜X21˜X29;
• (Id) X28˜Glu˜X21˜X29;and (Ie)
• pharmaceutically acceptable salt thereof, wherein:
• each X21 is independently a small residue;
• each X22 is independently a basic residue;
• each X24 is independently a hydrophobic residue;
• each X25 is independently an aromatic residue;
• each X26 is independently a polar residue;
• each X27 is independently a small or a cysteine-like residue;
• each X28 is independently a small or an acidic residue;
• and
• each X29 is independently any residue;
• and
• each “˜” independently represents an amide, a substituted amide, an isostere of an amide or an amide or peptido mimetic linkage.