Introduction

• An allergic response due to sensitization to insect or arachnid salivary allergens. Most common hypersensitive skin disease Skin: parasitic disease - overview.
• Signs: pruritus, papules, nodules, urticaria Urticaria and angioedema.
• Cause: fleas (most common) Skin: flea bite hypersensitivity ; mites, egCheyletiella Skin: cheyletiellosis ;Trombicula Neotrombicula autumnalis; lice Skin: pediculosis ; ticks Ixodes ricinus Ixodes canisuga Ixodes hexagonus , mosquito; bees and wasps Insect stings and envenomation.
• Treatment: anti-inflammatory medication. Avoid exposure if possible.
• Prognosis: varies with arthropod involved.
• See Parasitic Skin Disease - overview Skin: parasitic disease - overview.

Pathogenesis

Etiology

• Fleas Ctenocephalides felis Ctenocephalides canis.
• Mites (especiallyCheyletiella Cheyletiella yasguri Skin: cheyletiellosis ,Trombicula autumnalis Neotrombicula autumnalis Skin: neotrombicula autumnalis infestation ,Sarcoptes scabiei Sarcoptes scabiei Skin: sarcoptic mange ).
• Lice Skin: pediculosis.
• Ticks Ixodes canisuga Ixodes hexagonus Ixodes ricinus.
• Bees, wasps, hornets Insect stings and envenomation.
• Mosquitoes.
• Other biting flies, egStomoxys calcitrans.
• ?Ants.

Pathophysiology

• Toxins and excretory products produced by ectoparasites act as direct irritants and/or via their potential as allergens.

Timecourse

• Generally sudden onset (in contrast to atopy Skin: atopy ).

Epidemiology

• Variable depending on insect or arachnid involved.
• Some live permanently/semi-permanently on host, egCheyletiella, lice. Others are 'visitors', eg mosquitoes, bees.

Diagnosis

Treatment

Prevention

Outcomes