Thong et al. (2005) [1736] in a study of anaphylaxis in adults referred to a Singapore clinic found that ingestion of mollusks (abalone and limpet) was the most common cause of food related anaphylaxis with 11/30 cases.

Lopata et al (1997) [1188] divided the symptoms of 38 patients with allergy to seafood into four categories: cutaneous, gastrointestinal, respiratory, and others. Respiratory reactions were more frequent in subjects who also had other atopic diseases. Although most of the subjects (66%) reported symptoms within 2 hours of food ingestion, a significant number of subjects (13; 34%) only reacted between 2 and 7 hours after eating. In both groups the majority of the subjects (76% and 69%, respectively) experienced cutaneous and respiratory symptoms, whereas the remaining subjects were first seen with gastrointestinal symptoms. Zinn et al (1997) [1299] described these patients together with additional fin fish and crustacea allergic patients. Reaction to abalone (also called perlemoen) was the third most common reaction to sea food after shrimps and crawfish with 38/105 patients reacting to abalone. Symptoms were not listed by food but it was noted that abalone caused several severe reactions.

Maeda et al. (1991) [1696] report 11 patients who developed moderate to severe anaphylactic reactions following ingestion of grand keyhole limpet (GKL) and abalone. Some of these patients may also have been amongst those described by Morikawa et al. (1990) [1694] who reported 5 abalone allergic individuals. 2 of the individuals studied by Morikawa et al. (1990) only reacted 90 minutes to 3 hours after eating.

Dohi et al (1991) [318] reported a single case of exercise induced anaphylaxis to abalone.

One of the first cases of allergy to abalone was reported by Clarks (1979) [1737].

Wu & Williams (2004) [1709] made abalone and limpet extracts by cold extraction of cooked shellfish in sterile PBS overnight. The extracts were centriguged at 50000 x g and the supernatants concentrated using Centricon YM-3 filter units (Millipore) to 20 mg/ml. Before use the extracts were sterile filtered and diluted 1:1 v/v with sterile glycerine.

Lopata et al (1997) [1188] made five in-house extracts (abalone, oyster, black mussel, white mussel, and squid) diluted in 50% glycerol (vol/vol) and used one commercial blue mussel (Mytilus edulis) extract (Soluprick, ALK Laboratories, Horsholm, Denmark). Extracts were made from the edible portions which were cut into small pieces and tumbled overnight at 4° C in phosphate-buffered saline (PBS). After centrifugation at 1000 x g for 15 minutes, the extracts were sterilized by sterile filtration (0.45 µm; Millipore), and the protein content was determined by using a dye-binding method (BCA-protein assay, Pierce) and stored in aliquots (100 µl) at –20° C.

Morikawa et al. (1990) [1694] minced grand keyhole limpet, abalone, carp and baby abalone-like shellfish and made 10% extracts in water for 48 hours. After centrifugation at 1000 x g for 30 minutes, the extracts were filtrated, lyophilised and stored at 4° C. Keyhole limpet haemocyanin was from Sigma (St Louise, USA). Skin tests used 490 µg/ml, 1.6 mg/ml and 380 µg/ml for grand keyhole limpet, keyhole limpet haemocyanin and abalone diluted in 50% v:v glycerol.

Wu & Williams (2004) [1709] defined a positive SPT as 3 mm greater than the negative control.

Lopata et al (1997) [1188] read SPTs after 15 minutes. These were considered to be positive if the diameter of the wheal was at least 3 mm greater than that produced by the negative control, saline and glycerol. Histamine dihydrochloride (10 mg/ml) was used as a positive control.

Morikawa et al. (1990) [1694] read SPTs after 20 minutes. These were considered to be positive if the diameter of the wheal was at least 5 mm greater than that produced by the negative control of saline.

Wu & Williams (2004) [1709] tested 84 patients who reported shellfish allergy.

Lopata et al (1997) [1188] reported skin prick tests from 24 patients; 10 patients were excluded because they had reported very severe symptoms and 4 of the 38 seafood allergic patients identified were unable to attend.

Maeda et al. (1991) [1696] and Morikawa et al. (1990) [1694] report  skin prick tests on 11 and 5 patients respectively.

Wu & Williams (2004) [1709] aimed to use SPT to diagnose to which shell fish their patients were allergic. They reported that 70 patients gave positive SPTs to a shellfish and that 45 patients were sensitised (i.e. SPT positive) to abalone and/or limpet. 27 of these were also sensitised to crustacea. Limpet gave more positive SPTs (40%) than abalone (26%).  

Lopata et al (1997) [1188] report 14/24 positive SPTs for abalone, 9/24 for oyster, 10/24 for black mussel, 6/24 for blue mussel, 5/24 for white mussel and 7/24 for squid.  

Maeda et al. (1991) [1696] and Morikawa et al. (1990) [1694] report positive SPT in their patients to either abalone or grand keyhole limpet. 4/5 patients of Morikawa et al. (1990) reacted to grand keyhole limpet (1 of these had reacted after eating abalone) and 1/5 to abalone (the abalone positive child had reacted after eating grand keyhole limpet). Only 1/3 reacted to haemocyanin.

Lopata et al (1997) [1188] tested sera from 38 patients who had reported symptoms with abalone and 10 fin fish sensitive controls.

Maeda et al. (1991) [1696] and Morikawa et al. (1990) [1694] tested sera from 11 and 5 patients respectively.

Lopata et al (1997) [1188] reported that 45% of all sera tested (17 of 38) gave an elevated RAST value (as % binding of IgE to abalone). Of the patients with positive RAST responses to abalone, 8 of 17 also had elevated IgE to snail. Individuals with negative SPT responses had little or no IgE reactivity to the abalone by RAST. 6 of the patients who had negative responses to RAST tests, had positive responses to SPTs (probably reflecting limitations of the RAST analysis).

Maeda et al. (1991) [1696] reported a positive RAST for 11 patients. Morikawa et al. (1990) [1694] reported positive RAST for 5 patients with grand keyhole limpet and abalone.  Keyhole limpet hemocyanin and baby abalone-like extract was RAST positive with the 3 and 2 sera tested. RAST inhibition revealed cross antigenicity between grand keyhole limpet, abalone and keyhole limpet hemocyanin. Morikawa et al. (1990) reported that 1 sera was RAST positive for carp but that there was no RAST inhibition of the mollusc extracts with the carp extract.