A new symptom dubbed ‘black-nose’ disease has been reported among chikungunya-infected patients, characterized by darkening skin on the nose. Caused by damaged blood vessels and reduced oxygen flow, this symptom points to the virus’s severe impact on the circulatory system. Experts are studying its implications on long-term health.
As new cases of chikungunya are being reported in the country, an unprecedented symptom —blackening of the nose — has emerged. Should you be concerned? Will it help diagnose the fever more efficiently?
A month-old toddler girl in Hyderabad was taken to a skin clinic because her face, especially around the nose, had developed dark patches. These dark areas spread to the sides of her nose. Her mother had been diagnosed with chikungunya, a viral infection, one week before giving birth. The mother had symptoms like fever and joint pain for about a week, and the infection was confirmed by a blood test.
At 15 days old, the baby also developed a fever and became irritable. A week later, the dark patches appeared, but they did not cause her any discomfort. Doctors examined her and noticed small, flat dark spots over her nose.
Based on the baby’s condition, the doctors diagnosed her with post-chikungunya hyperpigmentation, also known as Chik Sign, a skin condition likely caused by the mother’s chikungunya infection.
Since the baby was otherwise healthy, no blood tests were done, especially as the mother did not want her baby’s blood drawn for tests. Doctors reassured the mother that the dark spots were harmless and treated the baby with a simple moisturiser (liquid paraffin) to keep the skin soft.
Rare case of a newborn with Chik Sign
As new cases of chikungunya are reported in the country, an unprecedented symptom —blackening of the nose — has emerged.
Typically, patients with chikungunya experience symptoms such as sudden-onset high fever, severe joint pain (especially in the hands, wrists, ankles, and feet), headache, muscle pain, fatigue, and a rash that often appears red and flat after the fever subsides. This season, however, blackening of the nose was also observed.
Chikungunya variant
In Maharashtra, which has reported around 2,643 cases, Pune is among the worst affected cities, with over 2,000 cases. A new variant of the chikungunya virus is causing severe and unusual symptoms, including paralysis, blackening of the nose, and dangerously low platelet counts —symptoms never previously associated with chikungunya.
Patients affected by the blackening of the nose find it difficult to move around socially; the disfigurement lasts for around two weeks and around 20 percent of the patients are presenting with this condition.
Nose colour for diagnosis
Hyderabad based physician Dr Sai Kiran Chilukuri explained that the distinctive pigmentation, which is known as ‘chik sign’ or ‘brownie nose’ is usually a self-resolving condition, and could be a useful symptom to help diagnose the condition, especially in resource poor regions where tests might be too expensive.
What is Chikungunya?
Chikungunya is a viral infection, transmitted by the bite of the Aedes mosquito. Fever, joint pain, and skin manifestations are usually associated with this infection.
“The chik sign typically appears as macular (flat), speckled hyperpigmentation over the tip and alae (wings) of the nose. This pigmentation can extend to the bridge and sides of the nose. It usually develops a few weeks after the acute febrile phase, as the fever and rash are resolving. The pigmentation can persist for up to six months after the initial chikungunya infection,” Dr Chilukuri said, explaining that the exact cause of chik sign is not fully understood.
It is thought to result from post-inflammatory hyperpigmentation triggered by the chikungunya virus. This striking centrofacial pigmentation can mimic other conditions, such as melasma.
“Chik sign is a useful clinical marker for diagnosing chikungunya infection, especially in resource-limited settings where serological testing may not be available. Although it can persist for months, it typically resolves on its own over time. Knowledge of this cutaneous feature can assist in diagnosing chikungunya,” Dr Chilukuri said.
“These symptoms usually appear four to eight days after being bitten by an infected Aedes mosquito. While fever may resolve within a few days, joint pain can last for weeks or even months. In rare cases, complications such as heart, neurological, or gastrointestinal issues may occur, particularly in those with pre-existing health conditions,” said Dr Chilukuri.
Chik sign typically lasts for up to six months after the onset of chikungunya fever. In some cases, the pigmentation may resolve in about four weeks, depending on individual factors and treatment interventions. The pigmentation is generally asymptomatic and resolves over time, often requiring only conservative management, such as sun protection and topical treatments.
Dr Chilukuri said treatment for chik sign involves conservative management, as the condition is generally asymptomatic and self-limiting.
What is the recommended approach?
Sun Protection: Patients are advised the use of sun protection to prevent further darkening of the pigmentation. This includes applying broad-spectrum sunscreen when exposed to sunlight to minimize UV-induced melanin production.
Topical Moisturisers: Regular application of moisturisers helps maintain skin hydration, which can aid in the healing process.
Topical Treatments: Agents such as kojic acid and hydroquinone (4 percent concentration) can be used to reduce pigmentation. These treatments inhibit melanin production and can lead to gradual improvement over time.
Patient Reassurance: Patients will need to be assured that the pigmentation is temporary and benign, and will resolve in time. Reducing stress on account of the changed appearance is necessary.
Chikungunya, first identified in Tanzania
Chikungunya is a viral disease transmitted by mosquitoes, caused by the chikungunya virus (CHIKV). It was first identified in 1952 during an outbreak in Tanzania. The name “chikungunya” comes from the Makonde language, meaning “to become contorted,” which reflects the stooped posture of those suffering from severe joint pain associated with the illness.
Chikungunya tends to have cyclic outbreaks, occurring roughly every four to eight years. The disease is especially common in tropical regions where Aedes mosquitoes are prevalent.
In 1963, India reported its first chikungunya outbreak in Calcutta (now Kolkata), West Bengal. The following year, outbreaks were reported in Chennai, Pondicherry, and Vellore, with other affected areas including Visakhapatnam, Kakinada, Rajahmundry, and Nagpur.
From 1965 to 1973, chikungunya outbreaks continued across various parts of India, with the last notable outbreak of the 20th century recorded in Barsi, Maharashtra, in 1973.
The disease re-emerged with significant intensity in the 2000s. From 2005 to 2010, India experienced major chikungunya outbreaks of unprecedented magnitude, with over 1.25 million suspected cases reported in the worst-hit states. After this period, reported cases dropped significantly.
However, in 2016, India faced another massive outbreak with 64,057 confirmed cases across the country. Since then, chikungunya has become endemic throughout India, with regular outbreaks causing significant economic and productivity losses.
The virus has evolved over time, with several mutations identified in the circulating strains.
This year, by early September, Maharashtra recorded 2,643 confirmed cases and Uttar Pradesh around 4,345 cases; there were 1,358 cases in the southern states, with 11 in Telangana.
Skin and mosquito-borne diseases
Differentiating chikungunya from other mosquito-borne diseases based on skin symptoms involves examining the specific cutaneous manifestations associated with each illness. Here is a comparison of chikungunya with other common mosquito-borne diseases like dengue and Zika.
Chikungunya
Rash: Typically presents as a maculopapular (a flat red area on skin covered with small bumps) rash, which may appear later in the course of the disease, often after the onset of fever and joint pain. The chik sign, characterised by hyperpigmentation on the nose, can develop during or after the acute phase.
Joint pain: Severe joint pain is a hallmark symptom, often debilitating and symmetric, affecting small joints (hands, wrists, ankles) and larger joints (knees, shoulders).
Dengue
Rash: The rash can vary widely but may present as a flushed appearance or petechiae (small red spots) due to bleeding under the skin. It can also lead to more serious complications like hemorrhagic fever.
Other symptoms: Dengue often includes severe headache, retro-orbital pain, muscle and joint pain (though typically less severe than chikungunya), nausea and vomiting, and can lead to complications such as thrombocytopenia (low platelet count) and bleeding.
Zika
Rash: Zika virus typically causes a mild maculopapular rash that appears in conjunction with fever and joint pain. The rash is generally less pronounced than in chikungunya.
Other symptoms: Zika symptoms are usually milder and may include conjunctivitis (red eyes), muscle pain, and headache. Notably, Zika poses significant risks during pregnancy, potentially leading to congenital issues like microcephaly.
“Chikungunya and dengue have appeared simultaneously in the past, as both are transmitted by the same mosquito. We are now seeing cases where platelet counts are dropping to as low as 5,000, and CPK (creatine phosphokinase) levels are significantly elevated. Severe myositis is leading to an inability to walk. It’s primarily affecting people in 45 to 65 age group. Nerve conduction studies were performed, and it is quadriplegia, not myositis. No such cases have been observed among children so far, though some have shown signs of encephalitis, which is a known complication with both dengue and chikungunya,” said Dr Sivaranjani Santosh, Hyderabad based paediatrician. #hydkhabar
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Ahssanuddin Haseeb 
Faraaz Mohammed