Phototherapyin Skin Disease and Care- Includes UVB (narrowband or broadband) and UVA (UVA1 or UVA2 ± psoralen)
- CI: photosensitizing medication (i.e., thiazides) and photosensitive disorders (i.e., lupus)
- Broadband UVB (290–320 nm): emits light in broad range, not used as frequently now
- Excimer Laser (308 nm): targeted phototherapy for recalcitrant psoriatic lesions
- Narrowband UVB (NBUVB) (311–313 nm): narrower spectrum relates to better therapeutic effect than broadband
- Possible mechanism of action: UV light absorption by chromophores (i.e., nuclear DNA) resulting in DNA photoproducts like pyrimidine dimers, ↓ cellular proliferation, apoptosis of T cells, suppression of Langerhans cells
- Erythema after 4–6 h, peaks at 12–24 h; can use in pregnant women and children
- SE: erythema/blistering (acute), photoaging, carcinogenesis
- UVA: UVA2 (320–340 nm, similar to UVB) and UVA1 (340–400 nm, penetrates deep)
- PUVA (typically peaks at 352 nm): UVA + psoralen (type of furocoumarin, topical or oral)
- Oral psoralen (i.e., methoxsalen): peak concentration occurs 1.5 h after ingestion
- Ocular toxicity: may detect psoralen in lens for up to 12 h after ingestion, thus patients to avoid sun exposure for 24 h after PUVA treatment
- Mechanism of action: intercalates into DNA, forms reactive oxygen species (ROS), alters cytokine expression, ↓ cellular proliferation, results in apoptosis of T cells, and suppresses Langerhans cells
- Erythema after 24–36 h later and peaks at 48–96 h
- SE: diffuse hyperpigmentation, nausea, vomiting, stinging, pruritus (may be intense), PUVA lentigines, photoaging, carcinogenesis
- Extracorporeal photochemotherapy (ECP): extracorporeal UVA irradiation of WBCs after 8-MOP added, then returned back to patient; used in treatment of erythrodermic CTCL
- Photodynamic therapy (PDT): 400–700 nm
- Topical 5-aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) transformed into protoporphyrin IX (higher amounts found in tumors); with exposure to red or blue light, ROS produced and selectively destroys premalignant and malignant cells
- Therapeutic wavelength between 400 and 800 nm but typically blue light (near 400 nm) chosen due to large porphyrin absorption peak
| | | | | | | Table 7-9 Miscellaneous Drugs | | | Name | | Mechanism of Action | | Others | | | Cochicine | | Alkaloid preventing microtubule assembly (metaphase arrest), decreases neutrophil chemotaxis, degranulation, and adhesion | | Tx: neutrophilic dermatoses (Sweet’s, Behcet’s, etc.), aphthous stomatitis
SE: GI (diarrhea), peripheral neuropathy, myopathy | | | Potassium iodide
(SSKI) | | Likely suppresses neutrophil migration and toxicity
{Wolff-Chaikoff effect: inhibits thyroid hormone synthesis due to ↑↑ iodide (blocks organic iodine)} | | Treats: several types of panniculitis, neutrophilic disorders, sporotrichosis (cutaneous)
SE: acneifom eruption, hypothyroidism (check TSH 1 month after starting), iododerma | | | Gold | | Inhibits neutrophil/macrophage chemotaxis and phagocytosis, blocks prostaglandin synthesis | | Tx: severe DLE/SLE, bullous diseases
SE: lichenoid eruption, cheilitis, diarrhea | | | Calcipotriene
(Calcipotriol) | | Synthetic vitamin D3 derivative, similar effect as calcitriol | | Cream, ointment, or lotion
SE: irritation, burning | | | Calcitriol
(1,25[OH]2D3) | | Active form of vitamin D3, inhibits keratinocyte proliferation | | SE: possible hypercalcemia, hypercalciuria | | | Anthralin
(Dithranol) | | Antiproliferative property; likely inhibits cell growth | | Topical used in psoriasis and alopecia areata
SE: odor, staining property, irritation | | | Coal tar | | Crude distillate; anti-inflammatory, antiproliferative properties | | Used for inflammatory dermatoses (psoriasis)
SE: odor, staining property, contact dermatitis | | | Hydroquinone | | Reversible depigmentation: inhibition of enzyme tyrosinase (blocks tyrosine to melanin) | | Used for melasma
SE: irritation, ochronosis (rare) | | | Alendronate,
Risedronate,
Pamidronate | | Bisphosphonate, inhibits osteoclasts with ↓ bone turnover, ↑ mineralization density of bone | | Used in long-term oral corticosteroid therapy
SE: severe musculoskeletal pain, osteonecrosis
CI: pregnancy, hypocalcemia, renal failure | | | Pentoxifylline | | Fibrinolytic and anti-thrombotic properties, improves blood flow | | Used for venous ulcers
SE: GI upset, dizziness | | | Glycopyrrolate | | Oral anticholinergic resulting in decreased sweating | | Used for hyperhidrosis
SE: anticholinergic symptoms | | | Pimozide
(Orap) | | Antipsychotic drug: blocks dopaminergic receptors in CNS | | Used in delusions of parasitosis
SE: prolongs QT interval, extrapyramidal reactions, tardive dyskinesia | | | Nicotinamide
(Niacinamide) | | Part of vitamin B group, anti-inflammatory property | | Topical formulation mainly used in dermatology | | | Azelaic acid | | Dicarboxylic acid; ↓ oxidative tissue injury with inflammation | | Used in postinflammatory hyperpigmentation, melasma, rosacea, acne; category B | | | Podophyllin | | Antimitotic, arrests cells in metaphase by binding tubulin | | Used for condyloma acuminata
Contraindicated in pregnancy | | | Benzoyl peroxide | | Bacteriostatic against P. acnes, causes oxidation of bacterial protein, keratolytic, desquamative | | SE: irritation, dermatitis, swelling, crusting, bleaching of colored fabrics and hair | | | Sulfur | | Antifungal, antibacterial, and keratolytic effect | | Often used with sodium sulfacetamide
SE: dryness, itching | | | | | | | |
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