Friday, September 28, 2007

Is tanning ever good for you? (Neonatal jaundice)

It is not uncommon for neonates to have high bilirubin levels, causing jaundice. This is because their livers are still immature and are not able to process heme at full capacity quite yet (decreased uptake and conjugation of bilirubin) and they have a higher red blood cell turnover rate than adults. The bilirubin deposits in the epithelium, causing the yellow tint in their eyes and skin. This could lead to more serious depositions in the nervous system, and possibly kerincterus.

The number one therapy is phototherapy, with blue, white, or green lights. Blue is best absorbed by the yellow bilirubin and helps metabolize it to water-soluble lumirubin, which can then be excreted. Green has a longer wavelength and may be better for protein-bound bilirubin. Phototherapy causes a systemic reduction in bilirubin levels.

Dennery PA, Seidman DS, Stevenson DK. Neonatal hyperbilirubinemia. N Engl J Med. 2001;344 :581 –590

Thursday, September 27, 2007

Is tanning ever good for you? (Psoriasis and eczema)

UV light has anti-inflammatory effects that can help control both psoriasis and atopic dermatitis. This treatment is used in both children and adults and is thought to be particularly effective for acute onset conditions. PUVA, UVB, and narrow-band UVB have all been used. PUVA requires the ingestion of a psoralen pill before treatment, which increases photosensitivity to UVA waves. Narrow band UVB is thought to have fewer side effects than normal UVB treatment.

There are lots of studies on the effectiveness of PUVA and UVB for psoriasis and eczema treatments. But this study discusses the mechanism of action of PUVA v, NB-UVB v cyclosporin.

Erkin G, Ugur Y, Gurer CK, Asan E, Korkusuz P, Sahin S, Kolemen F. Effect of PUVA, narrow-band UVB and cyclosporin on inflammatory cells of the psoriatic plaque.
J Cutan Pathol. 2007 Mar;34(3):213-9.


- PUVA is the only treatment that decreased Langerhans cells (CD1a+) in the epidermis
- All 3 treatments decreased T lymphocytes (CD4+ and CD8+)
- All 3 treatments reduced expression of CD86, an inflammatory stimulator

Wednesday, September 26, 2007

Is tanning ever good for you? (Acne)

Narrow band blue light (420 nm) has anti-inflammatory effects on acne. It is less useful for comedonal acne, where inflammation is less prevalent. The light attacks the heme metabolism mechanism of Propionibacterium acnes, therefore killing the bacteria. This study showed the antinflammatory effects of the blue light also. There was reduced staining of IL-1alpha and ICAM-1, both indicators of an inflammatory response. And with the addition of low-dose narrow band-UVB (312 nm), the results were even better.

Shnitkind E, Yaping E, Geen S, Shalita AR, Lee WL. Anti-inflammatory properties of narrow-band blue light. J Drugs Dermatol. 2006 Jul-Aug;5(7):605-10.

Tuesday, September 25, 2007

Is tanning ever good for you? (Prurigo)

Prurigo nodularis is a disease where the patient experiences intense itching at discrete points and due to scratching, rubbing, and picking develops thickening of the skin in the form of nodules +/- pigmentary changes. The etiology of the intense itching is unknown. Historically this is a very difficult disease to treat, and topical steroids and antihistamines are most commonly used to control the itching.

Tamagawa-Mineoka R, Katoh N, Ueda E, Kishimoto S. Narrow-band ultraviolet B phototherapy in patients with recalcitrant nodular prurigo. J Dermatol. 2007 Oct;34(10):691-5.

This study shows that narrow-band UVB is an effective treatment for recalcitrant prurigo nodularis. It does not recommend phototherapy as a first line, but only for those patients who have failed topical steroids or antihistamines.

Monday, September 24, 2007

Is tanning ever good for you? (CTCL)

Cutaneous T-cell Lymphoma is a category of diseases encompassing all lymphomas that are limited to the skin. There are multiple types of CTCL with different histological and clinical features. Emedicine has a simple overview of the different types, how they present, and whether they are typically indolent or aggressive. Mycosis fungoides is the most common type of CTCL and is predominantly an indolent disease.

A lot of research has been done on light therapy for early-stage Mycosis fungoides, and this is generally accepted as an effective first-line treatment. Both PUVA and UVB have been shown effective, but PUVA is associated with more side effects (erythema, carcinogenicity, nausea). In this study narrowband UVB and PUVA are compared.

Diederen PV, van Weelden H, Sanders CJ, Toonstra J, van Vloten WA. Narrowband UVB and psoralen-UVA in the treatment of early-stage mycosis fungoides: a retrospective study. J Am Acad Dermatol. 2003 Feb;48(2):215-9.

Narrowband UVB was found to have similar treatment efficacy and disease-free periods as PUVA.

Proposed mechanisms of action for narrowband UVB:
- increases allo-activating and antigen-presenting capabilities of Langerhans cells
- increases Il-2 and IL-6 production by keratinocytes
- increases TNF
- suppresses neoplastic T cells
- upregulates immune system

Propsed mechanisms of action for PUVA:
- mitotic inhibition
- killing neoplastic T cells
- psoralen might damage cell organelles or alter the immune system

In this study, PUVB, UVB, and PUVA are compared.

El-Mofty M, El-Darouty M, Salonas M, Bosseila M, Sobeih S, Leheta T, Nada H, Tawdy A, Amin I, El-Enany G. Narrow band UVB (311 nm), psoralen UVB (311 nm) and PUVA therapy in the treatment of early-stage mycosis fungoides: a right-left comparative study.Photodermatol Photoimmunol Photomed. 2005 Dec;21(6):281-6.

PUVB was not shown to have a significant advantage over UVB.

Caution should be used with light therapy treatments because of the risk of later carcinogenicity.

Friday, September 21, 2007

Is tanning ever good for you? (Vitiligo)

Vitiligo is believed to be an autoimmune depigmentation disorder. The exact cause is unknown, but it is believed that the body's immune system attacks its melanocutes (pigment-producing cells). Our country's most popular vitiligo patient is probably Michael Jackson.

Light therapy is thought to have a dual mechanism of action on vitiligo. First its anti-inflammatory effects reduce the destruction of melanocytes. Second the UV stimulation activates the remaining melanocytes. Pigment is more likely to persist in hair follicles, which is why repigmentation occurs around them.

Yones SS et al. Randomized double-blind trial of treatment of vitiligo: Efficacy of psoralen–UV-A therapy vs narrowband–UV-B therapy. Arch Dermatol 2007 May; 143:578-84.

This study was really well done and presents good evidence that narrowband UVB is more effective in vitiligo treatment. Although the data was not quite statistically significant (p=0.06 instead of p<0.05) between the two groups, there was some difference. Any study on vitiligo therapy will be inherently flawed because of the subjective nature in judging repigmentation, but the methods included examination under Wood's lamp, comparison of nonlesional skin and repigmented skin color, patient survey, and a quality of life index. The amazing thing is that all 50 patients showed improvement. Although the Nb-UVB patients had better color match, fewer side effects, and more repigmentation.

Controlled UV exposure is a proven treatment for vitiligo.

Thursday, September 13, 2007

Hair transplants in areas of scarring

The question came up today about whether or not hair transplants are feasible in areas of scarring. I found a number of studies addressing surgical repair of cicatricial (scarring) alopecia, in which the hair follicles are destroyed and replaced with scar tissue, so these studies should be relevant for any type of scarring on the scalp.

The older studies discuss surgical techniques including free flaps and tissue expansion. Tissue expansion involves using silicon implants to stretch skin where there is hair growth and create enough skin with naturally occurring hair follicles to use as a flap and replace the scarred scalp. It is difficult to just transplant hair/follicles into the scarred skin because of the decreased blood supply in scar tissue relative to normal scalp. This has a double-edged effect on the graft survival rate. Decreased blood supply means it is harder for the hair follicles to survive and grow, but also, the traumatized skin is more susceptible to infection and necrosis. Using flaps and skin grafts is risky because the procedure involves traumatized blood vessels for both the grafting site and the grafted skin, making it difficult for the new skin to survive.

New techniques use lasers to help with both preparation of the scarred skin and hair implantation, eliminating the need for a skin graft (which is really the riskiest part of the old procedures). A carbon dioxide laser was used to burn tiny holes into the scarred scalp, causing angiogenesis and increased blood supply to the scalp. In this case report, the success of the hair transplantation was attributed to the new vasculature. In another study, an Er:YAG laser was used to form the implantation holes for the hair follicles. Using the laser minimized trauma to the implantation site and was credited with a successful transplantation.

In summary, technology for hair transplants in scarred skin is quickly evolving into less risky and more successful procedures.

Kwon OS, Kim MH, Park SH, Chung JH, Eun HC, Oh JK. Staged hair transplantation in cicatricial alopecia after carbon dioxide laser-assisted scar tissue remodeling. Arch Dermatol. 2007 Apr;143(4):457-60.

Neidel FG, Fuchs M, Krahl D. Laser-assisted autologous hair transplantation with the Er:YAG laser. J Cutan Laser Ther. 1999 Dec;1(4):229-31.

Friday, September 7, 2007

Pressure sores in the WSJ

The Wall Street Journal talked about the measures hospitals and nursing facilities are taking to prevent pressure ulcers in this article. They are using fancy mattresses, playing music every 2 hours to remind nursing staff to turn the patients, and doing thorough skin checks more often. This is great news for patients, as ulcers are slow-healing, easily-infected, and preventable. They are also a significant part of the Medicare budget. But not for long. Medicare and some private insurers are slowly implementing a plan to stop paying for preventable conditions, such as pressure sores. I hope that they plan to increase compensation to facilities for the added cost of increased man hours and equipment. These are necessary and important measures to maintain a patient's quality of life, whether or not the improvement in care is cost-induced.