Papillary dermis

It is now widely used to treat many defects of the epidermis and papillary dermis in a variety of strengths, ranging from 20 to 70%, depending on the condition being treated [8]. 

Patients of varying skin types (1-V) having striae distensae alba on the abdomen or thighs can apply topical 20% glycolic acid daily to the entire treatment area. In addition, these patients apply 10% L-ascorbic acid, 2% zinc sulfate, and 0.5% tyrosine to half of the treatment area and 0.05% tretinoin emollient cream to the other half of the treatment area. The creams are applied on a daily basis for 12 weeks. Improvement is evaluated at 4 and 12 weeks with increased elastin content within the reticular and papillary dermis [14]. 

Jessner s Solution has been used for over 100 years as a therapeutic agent to treat hyperkera-totic epidermal lesions [1]. This superficial peeling agent constitutes a mixture of salicylic acid, resorcinol, and lactic acid in 95% ethanol. Jessner s solution causes loss of corneocyte cohesion and induces intercellular and intracellular edema. Jessner s typically induces wounding to the level of the papillary dermis. Historically, resorcinol (a key component of Jessner s peels) was used in concentrations of 10-50% in the early twentieth century. High concentrations of resorcinol were associated with side effects such as allergic contact dermatitis, irritant contact... 

Level 2 White frosting with areas of erythema showing through.This level of peel is indicative of a full-thickness epidermal peel to the papillary dermis and can be achieved with TCA concentration of >30%.This peel will result in full exfoliation of the epidermis (Fig. 4). 

Level 3 Solid white frosting with no erythema.This is indicative of penetration of TCA through the papillary dermis... 

Salicylic acid has a keratolytic effect, thus eliminating superficial pigmented keratinocytes and stimulating cells turnover. This superficial peeling allows TCA to act a low concentration to remove pigmented keratinocytes through papillary dermis (see Fig. 14.12). 

Superficial chemical peels, including salicylic and glycolic acids, and Jessner s peels target the stratum corneum to the papillary dermis. These agents can be safely used to facilitate the resolution of PIH (Figs. 16.2,16.3,16.4 and 16.5). To assess for variability in response and limit further PIH, when possible, chemical peels should be initiated at the lower concentrations and titrated to higher concentrations if necessary to increase efficacy while minimizing side effects (see Darker Skin Section). 

Type XVI collagen is composed of 10 collagenous domains (COLI-COLIO) flanked by 11 NC domains. Type XVI collagen localizes near the dermal-epidermal junction. From immunoelectron microscopy of the papillary dermis, type XVI collagen associates with a fibrillin-1-containing matrix but not on collagen fibrils. ... 

The unique form of needle-free injection of powders into the epidermis or mucosa has been developed by researchers at the University of Oxford and Powderject Pharmaceuticals PLC (now PowderMed Ltd., United Kingdom). Drugs in microparticulate form are accelerated to sufficient velocities to enter the skin or mucosa and achieve a therapeutic effect (Burkoth et al. 1999). Provided the drug particles are sufficiently small to avoid skin lesions and pain, the concept has been shown to be clinically effective, pain-free, and applicable to a range of therapies. Use is pain-free because the penetration depth of the particles is typically less than 100 J,m into the epidermis, and thus the sensory nerve endings lying in the papillary dermis usually are not excited (Fig. 8.15). 

Figure 10.12 Theoretical estimation of the intracutaneous P02 profile. SC, stratum corneum ED, epidermis SP, papillary dermis SR, reticular dermis. Reprinted with permission from Ref. 168. Copyright 2002 Blackwell Publishing.

P-gp is constitutively expressed in nearly all barrier tissues. Techniques involving Northern blots (37) or Western blots with monoclonal antibodies such as C219 (38) and MRK 16 (39) have been used extensively to determine the tissue distribution of P-gp. It is expressed in adrenal cortex, kidney, liver, intestine, and pancreas endothelial cells at blood-tissue barriers, namely, the CNS, the testis, and in the papillary dermis (3,4,38,40,41). P-gp displays specific subcellular localization in cells with a polarized excretion or absorption function. More specifically, P-gp is found at the apical (AP) canalicular surface of hepatocytes, in the AP membrane of the columnar epithelial cells of colon and jejunum, and the AP brush border of the renal proximal tubule epithelium (3,4,40 1-2). In endothelial cells, P-gp is located in the luminal membrane (4,43). 

Xerosis with itch is present in more than 20% of patients with HIV infection, and most commonly is localized on the lower extremities.19 One study revealed the cutaneous neural tissue density within the papillary dermis and epidermis to be significantly decreased in HIV infected patients versus healthy controls.20 The study also reported significant differences in neuropeptide concentrations within HIV infected individuals. For example, calcitonin gene-related peptide (CGRP) was reduced in the epidermis in both the upper arms and legs, whereas substance P was found to be reduced only in the upper arms of HIV patients with itch. Dry skin and itch can also be induced iatrogenically via commonly prescribed medications for HIV such as indinavir etc. The standard in HIV treatment involves protease inhibitors, such as indinavir, which have been shown to induce dry skin and itch in over 40% of patients.21... 

The HA content of the dermis is far greater than that of the epidermis, and accounts for most of the 50% of total body HA present in skin.13 The papillary dermis has the more prominent levels of HA than does reticular dermis.138 The HA of the dermis is in continuity with both the lymphatic and vascular systems, which epidermal HA is not. Exogenous HA is cleared from the dermis and rapidly... 

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