Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android



APC: antigen-presenting cell

BCC: basal cell carcinoma

BPO: benzoyl peroxide

CBC: complete blood cell count

CLA: cutaneous lymphocyte-associated antigen

CTCL: cutaneous T-cell lymphoma

CTLA4: cytotoxic T lymphocyte–associated protein 4

CW: critical wavelength

DEET: diethyltoluamide (N,N-diethyl-m-toluamide)

5FU: 5-fluorouracil

GI: gastrointestinal

GM-CSF: granulocyte-macrophage colony-stimulating factor

G6PD: glucose-6-phosphate dehydrogenase

HDAC: histone deacetylase

HPA: hypothalamic-pituitary-adrenal

HPV: human papillomavirus

HSV: herpes simplex virus

IFN: interferon

IL: interleukin

IL-2R: IL-2 receptor

IV: intravenous

IVIG: intravenous immunoglobulin

Jak: Janus kinase

KS: Kaposi sarcoma

mAb: monoclonal antibody

MOA: mechanism of action

6MP: 6-mercaptopurine

MRSA: methicillin-resistant Staphylococcus aureus

mTOR: mammalian target of rapamycin

NSAID: nonsteroidal anti-inflammatory drug

OATP: organic anion-transporting polypeptide

ODC: ornithine decarboxylase

OTC: over the counter

PABA: p-aminobenzoic acid

PDE: phosphodiesterase

PDT: photodynamic therapy

PML: progressive multifocal leukoencephalopathy

PUVA: psoralen and UVA

RAR: retinoic acid receptor

RARE: retinoic acid–responsive element

RXR: retinoid X receptor

SC: subcutaneous

SPF: sun protection factor

SSRI: selective serotonin reuptake inhibitor

SSTI: skin and soft-tissue infection

STAT: signal transducer and activator of transcription

TCI: topical calcineurin inhibitor

TLR: toll-like receptor

TNF-α: tumor necrosis factor α

TSH: thyroid-stimulating hormone

UV: ultraviolet

VDR: vitamin D receptor

VZV: varicella zoster virus


The skin is a biologically active, multifunctional, and multicompartment organ. Medications can be applied to the skin for two purposes: to directly treat disorders of the skin and to deliver drugs to other tissues. Effective and safe use of topical pharmacological therapies requires an understanding of skin physiology and factors influencing percutaneous drug absorption and metabolism (Hwa et al., 2011; Wolff et al., 2008). General features of skin structure and percutaneous absorption pathways are outlined in Figure 70–1.

Figure 70–1

Cutaneous drug absorption. After application of a drug to the surface of the skin (stratum corneum), evaporation and structural/compositional alterations may occur that affect the drug’s ultimate bioavailability. The stratum corneum limits drug diffusion into the lower layers and thence into the body. A number of absorptive routes are possible, singly or in combination: between the cells of the stratum corneum (intercellular), across the corneal cellular layer (transcellular), and into the concavity of a hair follicle (follicular) with its associated sebaceous glandular cells and arrector pili muscle that is innervated by the sympathetic branch of the autonomic nervous system. Melanocytes and Langerhans cells are accessible in the lower epidermis. In the epidermal and dermal layers, drugs may also reach the eccrine glands (sweat glands) and their ducts. Permeation to the dermis brings a drug in contact with lymphatics (in green) and cutaneous vessels carrying arterial and venous blood (red and blue, respectively). These vessels provide an absorptive route into the general circulation. Deeper permeation to the hypodermis may also occur.

Nonpharmacological therapy is also used for treatment of skin diseases. ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.