Papular urticaria

papular urticaria, what you need to know

1. Papular Urticaria Prof. Dr. Essamelden Mohamed Mohamed Professor of Dermatology, Al-Azhar university   [email protected]

2. Papular urticaria is a common disorder manifested by chronic or recurrent papules caused by a hypersensitivity reaction to the bites of mosquitoes, fleas, bedbugs, and other insects.  Individual papules may surround a wheal and display a central punctum.

3. Etiology  A hypersensitivity or id reaction to bites from insects,   such as mosquitoes, gnats, fleas,   mites,   bedbugs,    caterpillars,   and moths.   This Photo by Unknown author is licensed under CC BY-SA . This Photo by Unknown author is licensed under CC BY-SA . This Photo by Unknown author is licensed under CC BY . This Photo by Unknown author is licensed under CC BY-NC-ND .

4. Pathogenesis  Type I hypersensitivity reaction Caused by a hematogenous disseminated antigen deposited by an arthropod bite  sensitive  patient  .  The causative antigen is unknown This Photo by Unknown author is licensed under CC BY-SA-NC . This Photo by Unknown author is licensed under CC BY-SA-NC . This Photo by Unknown author is licensed under CC BY-SA-NC . This Photo by Unknown author is licensed under CC BY-SA-NC .

5. Pathogenesis  The presence of immunoglobulin and complement deposits in the skin of some patients with papular urticaria suggests that the lesions may be due to a cutaneous vasculitis.   The deposits were most frequently seen in lesions within 24 hours of their development.  This Photo by Unknown author is licensed under CC BY-SA-NC .

6. Histopathology Mild subepidermal edema. Extravasation of erythrocytes. interstitial eosinophils, and exocytosis of lymphocytes.  This Photo by Unknown author is licensed under CC BY-SA .

7. Clinical Evaluation Itchy symmetrically distributed papules and papulovesicles  occur on any body part.  Common on exposed areas , particularly the extensor surfaces of the extremities.  A central hemorrhagic punctum.  Heal by hyperigmentation .

8. Differential Diagnosis Dermatitis Herpetiformis Id Reaction  Impetigo Insect Bites Pityriasis Lichenoides This Photo by Unknown author is licensed under CC BY-SA . This Photo by Unknown author is licensed under CC BY-SA . This Photo by Unknown author is licensed under CC BY-SA . This Photo by Unknown author is licensed under CC BY-ND .

9. Management

10. This Photo by Unknown author is licensed under CC BY-SA-NC .