Suppurative ulcerating iododerma -- a rare manifestation of inorganic iodide hypersensitivity

Risk of severe allergic reactions from the use of potassium iodide for radiation emergencies

Potassium iodide (KI) may be prescribed for widespread use in the event of a radiation emergency to prevent the uptake of radioactive iodide by the thyroid gland. The available literature was reviewed and expert opinion sought among members of the Adverse Reactions to Foods and the Adverse Reactions to Drugs and Biologicals Committees of the Academy to assemble evidenced-based conclusions regarding the risks of an allergic reaction to this therapy. This article describes the information leading to the following conclusions: (1) anaphylactoid reactions to radiocontrast media should not be considered evidence of KI allergy, (2) allergic contact dermatitis from iodine-containing antibacterial preparations should not be considered evidence of IgE antibody-mediated KI allergy or sensitivity, (3) IgE antibody-mediated allergy to seafood should not be considered evidence of KI allergy or sensitivity, and (4) physicians should ensure that persons are not allergic to inactive ingredients or components of the KI formulation prescribed.

Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications

Potassium iodide (KI) is a useful drug in the dermatologic armamentarium. It is successfully used for inflammatory dermatoses, most notably erythema nodosum, subacute nodular migratory panniculitis, nodular vasculitis, erythema multiforme, and Sweet's syndrome. KI is also successfully used for cutaneous and lymphocutaneous sporotrichosis. The precise mechanism by which KI acts is unknown. Although many minor side effects are common with this drug, major side effects can occur in pregnant patients and those with a history of kidney or thyroid disease. This article reviews the pharmacology, mechanism of action, indications, contraindications, and adverse effects of KI as a therapeutic agent.

Vegetating iododerma with underlying systemic diseases: report of three cases

Three patients with vegetating iododerma as a result of potassium iodide therapy are presented. The first patient had polyarteritis nodosa, the second had monoclonal gammopathy of undertermined significance, and the third had multiple myeloma. Vegetating iododerma probably represents an idiosyncratic response to iodides; patients with polyarteritis nodosa and paraproteinemias may be predisposed.

Suppression of thyroid radioiodine uptake by various doses of stable iodide

We studied the effect of various doses of sodium iodide on thyroid radioiodine uptake in euthyroid volunteers by giving single doses of 10, 30, 50, and 100 mg and then daily doses of 10, 15, 30, 50, or 100 mg for 12 days thereafter. All single doses above 10 mg suppressed 24-hour thyroid uptake of 123I to 0.7 to 1.5 per cent. Continued daily administration of 15 mg of iodide or more resulted in values consistently below 2 per cent. A small but statistically significant fall in serum thyroxine (T4) and triiodothyronine (T3) and a rise in serum thyrotropin (TSH) concentrations were observed after eight and 12 days of iodide treatment. These data suggest that the thyroid uptake of radioactive iodine can be markedly suppressed by single-dose administration of 30 mg of stable iodide and that suppression can be maintained with daily doses of at least 15 mg. This study provides guidelines for stable iodide prophylaxis in the event of exposure to radioactive iodine.