Pigment International

: 2022  |  Volume : 9  |  Issue : 3  |  Page : 231--233

“Chik sign” in chikungunya: three cases with dermoscopic findings

Sambasiviah Chidambara Murthy, Megha Shankar 
 Department of Dermatology and Venereology, Vijayanagar Institute of Medical Sciences, Ballari, Karnataka, India

Correspondence Address:
Sambasiviah Chidambara Murthy
Department of Dermatology and Venereology, Vijayanagar Institute of Medical Sciences, Ballari, Karnataka

How to cite this article:
Chidambara Murthy S, Shankar M. “Chik sign” in chikungunya: three cases with dermoscopic findings.Pigment Int 2022;9:231-233

How to cite this URL:
Chidambara Murthy S, Shankar M. “Chik sign” in chikungunya: three cases with dermoscopic findings. Pigment Int [serial online] 2022 [cited 2023 Mar 31 ];9:231-233
Available from: https://www.pigmentinternational.com/text.asp?2022/9/3/231/362407

Full Text


Chikungunya is a reemerging, mosquito-borne viral infection caused by the chikungunya virus, an arbovirus. It is characterized by high-grade fever, severe arthralgia, and various mucocutaneous manifestations.[1],[2] The term is derived from Makonde language, meaning “that which bends up” referring to the stooped posture of the affected patient due to severe joint pain.[3] Pigmentary changes, especially nose pigmentation and also known as the “Chik sign,” are characteristic of chikungunya.[2] Although reported earlier as specific for chikungunya, recently “Chik sign” has been reported in dengue and COVID-19 (covid nose).[4],[5] We report three cases of Chik sign with dermoscopic findings.

All the three were men aged between 26 and 49 years (mean age 40 years). They presented with asymptomatic pigmentary changes over the nose. History of fever, headache, and arthralgia preceded in all the cases. Details are described in [Table 1]. There was no drug intake or preceding dermatoses prior to the onset. On examination, multiple hyperpigmented macules and patches were seen over the dorsum of the nose including the tip and both alae [Figure 1]a and b, that is, classical centrofacial pigmentation of chikungunya fever. All patients had IgM antibodies for the chikungunya virus by enzyme-linked immunosorbent assay during the febrile episode.{Figure 1}{Table 1}

Routine hematological, biochemical, and urine examinations were normal. Dermoscopy (Dermlite DL3N Dermoscope, 3Gen, Inc. 31521 Rancho Viejo Road, Suite 104 San Juan Capistrano, CA 92675, USA) showed patulous follicular openings, pseudoreticular pigment network sparing follicles, brownish background, few dark brown globules, white scales, and bluish-grey globules [Figure 2]a and b. Skin biopsies were not consented to. All patients were advised strict photoprotection and topical 4% hydroquinone for 4 weeks with significant improvement.{Figure 2}

Chikungunya fever is a reemerging viral infection clinically characterized by an acute febrile illness associated with polyarthralgia, sore throat, conjunctivitis, and skin eruptions.[3] The “case definition” of chikungunya as per National Vector Borne Disease Control Programme 2016 guidelines is acute onset of fever, severe arthralgia/arthritis, with or without skin rash, and residing or having left an epidemic area 15 days prior to the onset of symptoms.[2]

Chikungunya fever may be seen in all age groups and both sexes. The incubation period is short (3–7 days), and the onset is acute without any prodrome. There is a high fever with chills and rigors. The fever may be biphasic (interval of 2–6 days) and is often associated with a maculopapular eruption. Constitutional symptoms include headache, diffuse myalgia, and arthritis, which is polyarticular, initially involving small joints of hands and feet, wrists, ankles, and later the larger joints. The disease is self-limiting, lasting for 1 to 7 days. However, in older individuals with compromised joints, the arthritic manifestations can persist from months to years because of subacute tenosynovitis. A chronic rheumatoid form of the disease occurs less commonly with recurrent, long-standing, arthritic symptoms.[1]

Various mucocutaneous features observed in chikungunya include pigmentary changes, maculopapular eruption, intertriginous aphthae-like lesions, transient nasal erythema, vesicobullous lesions, lichenoid eruptions, exacerbation of preexisting dermatoses, and subungual hemorrhage.[1],[3] Pigmentary changes usually appear after 1 to 3 weeks after the subsidence of fever.[5] Pigmentary changes include centrofacial (freckle-like macules),

diffuse pigmentation (involving face, pinna, and extremities), flagellate pigmentation (face and extremities), mucosal (tongue and palate), melasma-like over the face, lichen planus pigmentosus-like over neck and flexures, periorbital hypermelanosis, and pigmentation of existing acne lesions.[1],[3] In our cases, sudden onset, lack of palmar involvement, nail changes, absent weakness, anorexia, weight loss, postural hypotension, and electrolyte abnormalities helped in ruling out Addison disease and history of lack of drug intake helped to exclude drug-induced pigmentation.

The occurrence of pigmentary changes in chikungunya and its variable patterns are peculiar and the exact pathogenesis is still not evident. Some authors have suggested it be post-inflammatory.[3],[6] An increased intraepidermal melanin dispersion or retention triggered by the virus has been postulated as a cause.[6],[7] Ultraviolet rays are postulated to play a role, as they mainly affect the face in most patients.[2] In pigmentation confined to the epidermis, there is an increase in the production and transfer of the melanin to the surrounding keratinocytes. This could be possibly due to stimulation by prostanoids, cytokines, chemokines, other inflammatory mediators, and reactive oxygen species released during the inflammatory process. In the dermis, inflammation damages the basal keratinocytes, releasing large amounts of melanin, which is phagocytosed by macrophages (melanophages).[8]

Dermoscopic differential diagnosis includes lichen planus pigmentosus (currently classified under acquired dermal macular hyperpigmentation), which shows blue-grey globules around the eccrine and follicular openings, fixed drug eruptions showing diffuse bluish-grey pigmentation without a specific pattern, COVID-19 pigmentation showing areas of light to dark brown areas of reticular pigment network over the light brown background with perifollicular pigment clumping.[5],[9]

Histopathology shows a predominantly increase in epidermal basal layer pigmentation, although basal cell vacuolation and melanophages with lymphocytic infiltration in the dermis also has been reported.[2],[3] Correlating dermoscopic findings with histopathological features, brown background corresponds to melanin in the basal layer, brown pigment network to melanin in rete ridges, and pseudoreticular network to diffuse pigmentation perforated by follicular and eccrine openings. Patulous follicular openings correspond to dilated infundibulum, dark brown globules to increased melanin in the epidermis, white scale to hyperkeratosis, and bluish-grey globules to melanophages or free melanin in the dermis.

Diagnosis in our cases was based on classical clinical, serological findings and the course of the disease. To the best of our knowledge, dermoscopic findings of post-chikungunya pigmentation have not been described. Dermoscopic features in conjunction with clinical, serological, and histopathological findings help in proper diagnosis and management.


We thank Dr Balachandra S Ankad, Bagalkot, for his valuable opinion on dermoscopic images.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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