Dermoscopic criteria for discoid lupus erythematosus: An IJDVL study

Discoid lupus erythematosus (DLE) is a subtype of chronic cutaneous lupus erythematosus usually affecting the face and scalp but widespread involvement can occur. Dermoscopy is a non invasive, rapid and simple tool that helps in the early diagnosis of DLE thus preventing its sequelae. Recently a study proposing dermoscopic criteria for diagnosis of DLE was published in the Indian Journal of Dermatology, Venereology and Leprology.

Material and Method

An observational cross‑sectional study of 28 patients diagnosed as DLE by clinico-histopathological examination was conducted. Dermoscopic examination was done using polarized light (30x) and then a skin biopsy of the same lesion was taken. The study adopted the terminology approved in the last International Dermoscopy Society consensus. Data were analyzed using IBM SPSS software.

Results

Of the 28 studied patients, 20 (71.4%) were females and 8 (28.5%) were males; mean age was 39.7 ± 8.8 years. Fourteen (50%) patients had scalp lesions, 12 (42.9%) patients had lesion on the face, one (3.6%) on the chest and one (3.6%) on the arm. The median duration of lesions was 1.8 years. On dermoscopy, whitish patchy scales (25 cases, 89.3%) were the commonest finding followed by linear blood vessels (24, 85.7%) then follicular plugging (23, 82.1%) and pigmentation (23, 82.1%). Perifollicular whitish halos were observed in 19 (67.9%), white structureless areas in 19 (67.9%), rosettes in 16 (57.1%), a starburst pattern in 11 (39.3%) and follicular red dots in 10 (35.7%) of the studied patients.

Histopathology showed vacuolar interface dermatitis and periadenexal and perifollicular lymphoid infiltrate in 28 (100%) patients, follicular hyperkeratosis in 24 (85.7%), telangiectasia in 24 (85.7%), dermal fibrosis in 23 (82.1%), pigmentary incontinence in 22 (78.6%), perifollicular fibrosis in 21 (75%), surface hyperkeratosis in 21 (75%), dermal mucin deposition in 19 (67.9%), atrophy in 16 (57.1%), spotty parakeratosis in 13 (46.4%) and perifollicular red blood cells in 10 (35.7%) patients.

The results show significant agreement between many of the dermoscopic and pathological findings with high sensitivity especially for follicular plugging, linear blood vessels, scales, pigmentation and follicular red dots and high specificity for follicular plugging, perifollicular whitish halo, follicular red dots and linear blood vessels in the diagnosis of DLE.

The study shows that follicular plugging, follicular red dots and starburst pattern are abundant in lesions with short history in contrast to linear blood vessels and structureless whitish areas which are more in lesions with long history. With respect to the site of the DLE lesions, follicular plugging, perifollicular whitish halos and a starburst pattern showed highly significant correlations for lesions outside the scalp in contrast to structureless whitish areas which appeared more on scalp lesions.

The authors have proposed that follicular hyperkeratosis which occur at the middle of the hair follicle and the heavy infiltration around the sebaceous gland insertion could be the source of the optical reaction visible as rosettes on dermoscopy. Perifollicular fibrosis could be responsible for the larger rosettes which can also be noticed in many tumours and inflammatory skin lesions including DLE and therefore are not disease specific. side scalp. Starburst pattern may be related to the inflammatory infiltrate and dilated blood vessels round hair follicles

DLE can be differentiated on dermoscopy from other lesions by the following features-

1. subacute cutaneous lupus shows whitish scaling associated with mixed vascular pattern with the absence of pigmentation and follicular plugging
2. sarcoidosis shows diffuse or localized, structureless, orange areas and well‑focused linear or branching vessels
3. granuloma annulare shows unfocused vessels on a pinkish‑reddish background and focal or diffuse yellowish‑orange and whitish areas
4. cutaneous leishmaniasis is characterized by polymorphic vascularization, erythema, whitish or yellowish follicular plugs with rounded, oval, or tear‑drop shape, white starburst‑like pattern, scales and crusts
5. granuloma faciale shows prominent follicles, branching linear vessels and brown globules.

To conclude this study demonstrates the usefulness of dermoscopy in the early diagnosis of DLE with some site specific features which can lead to decrease in sequelae like scarring due to prompt treatment.

References-

1. Fathy H, Ghanim BM, Refat S, Awad A. Dermoscopic criteria of discoid lupus erythematosus: An observational crosssectional study of 28 patients. Indian J Dermatol Venereol Leprol 2022;88:360-6.