Hair microscopy: an easy adjunct to diagnosis of systemic diseases in children

Abstract

Hair, having distinct stages of growth, is a dynamic component of the integumentary system. Nonetheless, derangement in its structure and growth pattern often provides vital clues for the diagnosis of systemic diseases. Assessment of the hair structure by various microscopy techniques is, hence, a valuable tool for the diagnosis of several systemic and cutaneous disorders. Systemic illnesses like Comel-Netherton syndrome, Griscelli syndrome, Chediak Higashi syndrome, and Menkes disease display pathognomonic findings on hair microscopy which, consequently, provide crucial evidence for disease diagnosis. With minimal training, light microscopy of the hair can easily be performed even by clinicians and other health care providers which can, thus, serve as a useful tool for disease diagnosis at the patient's bedside. This is especially true for resource-constrained settings where access and availability of advanced investigations (like molecular diagnostics) is a major constraint. Despite its immense clinical utility and non-invasive nature, hair microscopy seems to be an underutilized diagnostic modality. Lack of awareness regarding the important findings on hair microscopy may be one of the crucial reasons for its underutilization. Herein, we, therefore, present a comprehensive overview of the available methods for hair microscopy and the pertinent findings that can be observed in various diseases.

Keywords: Diagnosis; Disease; Hair; Microscopy; Primary health care.

Fig. 1

Hair microscopy findings in Griscelli syndrome type 2 visualized using a high power objective (40X); left panel: light microscopy showing large coarse clumps of melanin distributed in the cortex in an irregularly irregular pattern; right panel: polarized light microscopy showing uniformly white color of the hair shaft

Fig. 2

Hair microscopy findings in Chediak Higashi syndrome visualized using a high power objective (40X); left panel: light microscopy showing small fine clumps of melanin distributed in the cortex in a regularly irregular pattern; right panel: polarized light microscopy showing variegated colors of the hair shaft

Fig. 3

Light microscopy findings of hair in Menkes disease; left panel: low power view showing twisting of the hair shaft on its longitudinal axis called ‘pili torti’; middle and right panels: high-power views showing trichorrhexis nodosa