Wood's lamp

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A black light bulb. To the human eye, the light looks much more violet.

A Wood's lamp is a diagnostic tool used in dermatology by which ultraviolet light is shone (at a wavelength of approximately 365 nanometers) onto the skin of the patient; a technician then observes any subsequent fluorescence. For example, porphyrins — associated with some skin diseases — will fluoresce pink.

Contents

[edit] History

Though the technique for producing a source of ultraviolet light was devised by Robert Williams Wood in 1903 using "Wood's glass", it wasn't until 1925 that the technique was used in dermatology by Margarot and Deveze for the detection of fungal infection of hair.

[edit] Clinical use

It has many uses, both in distinguishing fluorescent conditions from other conditions, and in locating the precise boundaries of the condition.

[edit] Fungal and bacterial infections

It is also helpful in diagnosing:

[edit] Ethylene glycol poisoning

Furthermore, a Wood's lamp may be used to rapidly assess whether a subject is suffering from ethylene glycol poisoning as a consequence of antifreeze ingestion.

Manufacturers of ethylene glycol-containing antifreezes commonly add fluorescein, which causes the patient's urine to fluoresce under Wood's Lamp.[2]

[edit] Other

Wood's light is useful in diagnosing conditions such as tuberous sclerosis[3] and erythrasma.[4] Additionally, detection of Porphyria Cutanea Tarda can sometimes be made when urine turns pink upon illumination with Wood's lamp.[5]

Its use in detecting melanoma has been reported.[6]

[edit] See also

[edit] References

  1. ^ Prevost E (October 1983). "The rise and fall of fluorescent tinea capitis". Pediatr Dermatol 1 (2): 127–33. doi:10.1111/j.1525-1470.1983.tb01103.x. PMID 6680181. 
  2. ^ Winter ML, Ellis MD, Snodgrass WR (June 1990). "Urine fluorescence using a Wood's lamp to detect the antifreeze additive sodium fluorescein: a qualitative adjunctive test in suspected ethylene glycol ingestions". Ann Emerg Med 19 (6): 663–7. doi:10.1016/S0196-0644(05)82472-2. PMID 2344083. http://linkinghub.elsevier.com/retrieve/pii/S0196-0644(05)82472-2. 
  3. ^ "Photo Quiz - April 1, 2007 -- American Family Physician". http://www.aafp.org/afp/20070401/photo.html. 
  4. ^ Morales-Trujillo ML, Arenas R, Arroyo S (July 2008). "[Interdigital erythrasma: clinical, epidemiologic, and microbiologic findings.]" (in Spanish; Castilian). Actas Dermosifiliogr 99 (6): 469–73. PMID 18558055. http://www.elsevier.es/revistas/0001-7310/99/469. 
  5. ^ Le, Tao & Kendall Krauase. First Aid for the Basic Sciences - General Principles. McGraw-Hill Medical, New York: 2008.
  6. ^ Paraskevas LR, Halpern AC, Marghoob AA (2005). "Utility of the Wood's light: five cases from a pigmented lesion clinic". Br. J. Dermatol. 152 (5): 1039–44. doi:10.1111/j.1365-2133.2005.06346.x. PMID 15888167. 

[edit] External links

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