Onset Of Erythema Research Articles

The influence of urea on percutaneous absorption.

The release characteristics of aqueous and oily creams (BP) containing urea up to concentrations of 10% have been studied. The results show that the urea has little influence on the ability of the formulation to release its active ingredient, in this case, hexyl nicotinate. The preparations were then assessed in an in vivo experiment by measuring the time of onset of erythema induced by the hexyl nicotinate. The urea influenced the time of onset of erythema, and a mechanism for its action is proposed.

Pott's Puffy Tumor A Clinical Marker for Osteomyelitis of the Skull

In 1771, Sir Percivall Pott1described a condition in which massive soft-tissue swelling of the scalp was associated with an underlying osteomyelitis of the skull. This swelling is known as Pott's puffy tumor. Sporadic cases reported in the literature have included both adults and children.2Herein, we report such a case that occurred in an elderly man. Report of a Case A 74-year-old man had been well until two months before examination, when he had noticed the gradual onset of erythema, mild scaling, and bogginess of the midforehead, without associated fever or tenderness. He was then seen by a physician in Mexico and was given an intramuscular injection of penicillin for presumed erysipelas; the soft-tissue swelling did not resolve. He was reevaluated by another physician, who performed a needle aspiration of the frontal scalp. The culture grew coagulase positiveStaphylococcus aureus, but a blood culture was negative for

Participation of Mast Cells and Complement in the Immediate Phase of Hematoporphyrin-Induced Phototoxicity

We have investigated the roles of mast cells and the complement system in the immediate phase of hematoporphyrin-induced phototoxicity in guinea pigs. Clinically, i.v. injection of hematoporphyrin, followed by irradiation with a light source containing 400-405 nm wavelength, resulted in the immediate onset of erythema and edema, which subsided partially in 30-60 min. This was followed by the appearance of delayed erythema and edema, which peaked at 6-12 h after irradiation. Histologic examination of the response of the immediate phase, using a 1 micron-thick section, revealed eosinophil infiltration and mast cell degranulation. The immediate phase of the clinical response was further quantitated by the extravasation of intravenously injected [125I]bovine serum albumin. Pretreatment of the guinea pig skin with the intradermal injection of compound 48/80 significantly suppressed the increase in vascular permeability induced by hematoporphyrin and irradiation (p less than 0.05). This hematoporphyrin-induced alteration in vascular permeability was also significantly inhibited by antihistamines, either H1 receptor antagonist alone (p less than 0.05) or a combination of H1 and H2 receptor antagonists (p less than 0.05). Guinea pigs depleted of complement also showed significantly less vascular permeability changes (p less than 0.05). These results indicate that functionally intact mast cells, and the complement system, are required for the full development of the immediate phase of phototoxicity induced by hematoporphyrin.

The human sunburn reaction: Histologic and biochemical studies

The ultraviolet-induced erythema reaction was investigated histologically and biochemically in four subjects, utilizing suction blister aspirates, analyzed for histamine and prostaglandin E 2 (PGE 2), and Epon-embedded l-μ skin biopsy sections from control skin and from irradiated skin at intervals for 72 hours after exposure to a Hanovia lamp. Major histologic alterations in the epidermis included dyskeratotic and vacuolated keratinocytes (sunburn cells), and disappearance of Langerhans cells. In the dermis the major changes were vascular, involving both the superficial and deep venular plexuses. Endothelial cell enlargement was first apparent within 30 minutes of irradiation, peaked at 24 hours, and persisted throughout the 72-hour study period. Mast cell degranulation and associated perivenular edema were first apparent at 1 hour and striking at the onset of erythema, 3 to 4 hours postirradiation; edema was absent and mast cells were again normal in number and granule content at 24 hours. Histamine levels rose approximately fourfold above control values immediately after the onset of erythema and returned to baseline within 24 hours. PGE 2 levels were statistically elevated even before the onset of erythema and reached approximately 150% of the control value at 24 hours. These data provide the first evidence that histamine may mediate the early phase of the human sunburn reaction and increase our understanding of its complex histologic and biochemical sequelae.

PROSTAGLANDIN ANTAGONISM BY SODIUM p‐BENZYL‐4‐[1‐OXO‐2‐(4‐CHLOROBENZYL)‐3‐PHENYLPROPYL]PHENYL PHOSPHONATE (N‐O164)

1 The ability of sodium p-benzyl-4-[1-oxo-2-(4-chlorobenzyl)-3-phenylpropyl]phenyl phosphonate (N-0164) to antagonize contractions produced by prostaglandins E2 and F2a on isolated preparations of gerbil, rat and guinea-pig gastrointestinal muscle has been studied. 2 N-0164 was found to be a potent, partially selective prostaglandin antagonist in these isolated smooth muscle preparations. The blockade produced by N-0164 in the isolated stomach strip of the rat had some, but not all, the characteristics of a competitive antagonism. 3 N-0164 produced a dose-dependent decrease in tone in the rat stomach strip that was abolished by pretreatment of the preparation with indomethacin. 4 N-0164 prevented diarrhoea induced by prostaglandin E2 in mice when given by intraperitoneal injection but was less effective when given orally. 5 N-0164 inhibited oedema induced with croton-oil and pyridine-ether in the mouse ear. 6 N-0164 delayed the onset of erythema following ultraviolet irradiation of guinea-pig skin only when an equimolar amount of pralidoxime chloride was added to the vehicle. 7 It is concluded that N-0164 is a potent, partially selective prostaglandin antagonist on several isolated smooth msucle preparations. N-0164 exhibits activity in vivo particularly following local application when problems associated with penetration and distribution are minimized.

The skin in magnesium-deficient rats.

The cutaneous vasodilatation occuring in the early stages of dietary deficiency of magnesium has been investigated in rats. While the time of onset of erythema varies in proportion to the weight of the animal, the duration is not related to weight. In severe states of vasodilatation, the skin is thickened and infiltrated with mononuclear cells, apparently derived from the blood. Intact sympathetic and sensory innervation are not necessary for the development of vasodilatation in the skin. Neither can the genesis of the erythema be attributed to degranulation of mast cells. From consideration of this and other investigations, it is concluded that the cutaneous abnormalities of magnesium-deficient rats cannot be due directly to hypomagnesaemia.

The effect of glycerol on the percutaneous absorption of methyl nicotinate.

Summary.— The effect of glycerol on the rate of percutaneous absorption of methyl nicotinate from aqueous vehicles was investigated. The partition coefficients of methyl nicotinate between isopropyl myristate and aqueous solutions of glycerol were determined. The diffusivity of methyl nicotinate in various aqueous solutions of glycerol was also studied. It was shown that addition of glycerol in concentrations above 60% delayed the onset of erythema in human skin. The results suggest that this effect is related to the partition coefficient and diffusivity of methyl nicotinate in the aqueous vehicle. The osmotic effects of glycerol are negligible.

The Action of Radium on Blood Supply: The White Reaction

After a surface application of radium the skin sometimes show a white or pale area corresponding to the part radiated. This precedes the erythema and is usually accompanied by slight œdema. When the thin, transparent, featherless skin overlying the pectoral muscle in the chicken is radiated with β radiation, a white discoloration appears in the underlying muscle two or three days later, and may persist until it is concealed by the onset of erythema in the overlying skin. This white reaction also occurs in tumours when they are radiated, a previously described.1 If a mouse or a new-born rat be inoculated subcutaneously with a small piece of tumour, the subcutaneous growth which arises appears pink through the translucent skin. If this tumour be radiated with β or γ radiation it will turn purple in a few days and subsequently white and bloodless. If it has been given a dose of radiation sufficient to cause it to disappear, then it will remain white or yellowish. If however, a sub-lethal dose has been given, then its normal pink colour will return and it will continue to grow. In old rats it is not possible to see these vascular changes on account of the opacity of the skin. They can, however, be demonstrated by inoculating large quantities of Indian ink into the tail vein.