Urticaria as a side-effect of diphencyprone therapy for resistant viral warts

Type II hypersensitivity involves IgG and IgM antibodies targeting cell surface antigens, leading to cell destruction. This can occur through complement activation, antibody-dependent cell-mediated cytotoxicity (ADCC), or acting as opsonins for phagocytosis. When excessive, these reactions cause significant tissue damage.Drug-induced hemolytic anemia is a common example, where drugs like penicillin or cephalosporins bind to red blood cells, forming drug-protein complexes. These complexes...

Chickenpox is an acute, highly contagious disease caused by the varicella-zoster virus (VZV), a double-stranded DNA virus belonging to the Herpesviridae family. Its transmission occurs primarily through the inhalation of respiratory droplets or direct contact with vesicular fluid from skin lesions. The incubation period typically ranges from 10 to 21 days, during which the virus replicates and disseminates through sequential phases within the host. Although generally self-limiting in children,...

Diphtheria is an acute, toxin-mediated infectious disease that primarily affects the upper respiratory tract. It is caused by Corynebacterium diphtheriae, a Gram-positive, pleomorphic rod that lacks spore-forming capability and exhibits a characteristic club-shaped morphology under microscopic examination. While C. diphtheriae can asymptomatically colonize mucosal surfaces, clinical disease manifests only when the bacterial strain is lysogenized by a specific β-corynephage. This phage...

Allergic reactions related to drugs are hypersensitivity responses driven by the immune system and bear no connection to the drug's therapeutic action. While drugs in isolation do not trigger an immune response, they can interact with endogenous proteins to form antigens. These antigens stimulate lymphocytes to produce antibodies. IgE-type antibodies attach themselves to mast cells. Upon subsequent exposure to the same stimulus, the antigen-antibody interaction is initiated, unleashing numerous...

Delayed-Type Hypersensitivity (DTH), or Type IV hypersensitivity, is a cell-mediated immune response. It occurs when T cells, rather than antibodies, mediate a reaction to specific antigens. It is characterized by a delayed onset (1-2 days) and involves the recruitment of macrophages to the inflammation site.The initiation of a DTH response begins with the sensitization of T cells. During this phase, which lasts at least 1-2 weeks, antigen-specific T cells are activated, clonally expanded, and...

Drug-related allergies are immune-mediated responses triggered by the administration of pharmacological agents. These hypersensitivity reactions are classified based on the immune mechanisms involved. The four primary types—Type I, II, III, and IV—are mediated by different immunological pathways and exhibit distinct clinical manifestations.Type I Hypersensitivity/ IgE-Mediated Reactions: Immunoglobulin E (IgE) immediately mediates Type I hypersensitivity reactions. Upon initial exposure to a...