Background: Calcium-binding proteins (polcalcins) and profilin are cross-reacting panallergens that sensitize a minority of pollen-allergic patients. Their clinical relevance remains controversial.

Objective: To assess the clinical relevance of hypersensitivity to polcalcin and profilin detected by skin prick test (SPT) in a large group of pollen-allergic patients.

Methods: Two hundred pollen-allergic adults (101 men, 99 women; mean age 34 years) underwent SPT with 9 pollens present in the geographical area of the study. Hypersensitivity to panallergens was detected by SPT with date palm polcalcin and profilin. Allergy to birch and/or cypress, grass and/or pellitory, and ragweed and/or mugwort were associated with 3 symptomatic periods, respectively, late February to mid-May, late April to mid-July, and mid-August to late September.

Results: Sixteen (8%) patients reacted to date palm polcalcin; 7/7 (100%) corecognized the grass polcalcin Phl p 7 in vitro. Clinically, only 4 (25%) had symptoms in all 3 seasonal periods. Forty (20%) patients reacted to profilin; only 32 (80%) reacted to cypress, and 22 (55%) to pellitory. Only 4 (10%) patients had symptoms during all 3 seasonal periods. Six patients (3%) were cosensitized to both polcalcin and profilin.

Conclusions: The clinical relevance of hypersensitivity to pollen panallergens is often limited; many allergic patients have symptoms only during the central period, suggesting primary grass sensitization. Profilin-allergic patients often do not corecognize pellitory and cypress pollen. In vivo component-resolved diagnosis of seasonal respiratory allergies is a promising approach that might lead to cost reduction and a faster definition of pollen-allergic cases.

Key words: Pollen allergy. Calcium-binding proteins. Polcalcin. Cross-reactivity. Skin prick test.