Journal of mycology and infection

Images in Mycology

Wood's Lamp Examination Findings of Tinea Capitis by Microsporum canis

Nuri Na,YongWoo Choi,Joonsoo Park
10.17966/JMI.2019.24.4.108 Epub 2020 January 06

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Abstract

Keywords

Microsporum canis Tinea capitis Wood's lamp

Wood's lamp examination is a non-invasive, cost-effective and useful diagnostic tool to allow detecting dermatological disorders. Wood's lamp produces an invisible long-wave ultra-violet radiation at the wavelength 340~450 nm (maximum at 365 nm)¹. It is mainly used to differentiate and localize diseases such as pigmentation disorders, porphyrias, and bacterial and fungal infections. Those dermatoses have their own characteristic fluorescence¹.

In fungal infection, wood's lamp helps giving impression to clinician of different species. Tinea versicolor shows yellowish-white or copper-orange². Tinea capitis shows blue-green (most Microsporum species)².

When gross viewed for the lesion, identified as Microsporum canis infection, observed eczema-like lesions (Figure 1A). A prominent blue green fluorescence can be identified by a wood's lamp test of the lesion (Figure 1B). Occasionally, tinea capitis can show dull yellow (by Microsporum gypseum) and dull blue (by Trichophyton schoenleinii)².

Tinea capitis commonly misdiagnosed such as seborrheic dermatitis, cellulitis, etc³. The misdiagnosed tinea capitis usually arises from unawareness of the disease that leads to inappropriate diagnostic approach. Wood's lamp test can be used as a useful diagnostic tool for clinicians by characterizing tinea capitis.

Figure 1. (A) 4 cm sized erythematous plaque with yellowish scale was seen on Left frontal area during 2 weeks. Potassium hydroxide (KOH) test was positive. (B) Blue-green characteristic fluorescence was seen under wood lamp.

PATIENT CONSENT STATEMENT

The patient provided written informed consent for the publication and the use of his or her images.

References

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