What is Chickenpox?
Chickenpox is a highly-contagious infection that is caused by the varicella-zoster virus. It is common in children under the age of 15, however can also present in adults.
Signs and symptoms of chickenpox
The characteristic progression of chickenpox is an uncomfortable, itchy rash that can progress to fluid-filled blisters and scabs [1]. The rash usually starts on the face, chest and back, and later spreads to the rest of the body [1].
As chickenpox is a viral disease, other symptoms may include fever, headache, tiredness and loss of appetite.
In some cases, the rash may spread to mucous membranes (most commonly the mouth), forming raised bumps that eventually transform into shallow ulcers [1, 2].
In more serious cases, chickenpox can present with dizziness, confusion, tachycardia (fast heart rate), shortness of breath, shaking, loss of muscle movement, cough, vomiting, stiff neck and being febrile (fever higher than 38.9 C) [3].
The disease usually lasts for 5 to 10 days.
Diagnosis of chickenpox
Chickenpox is diagnosed primarily by physical examination of the rash and the symptoms. It is important to arrange an appointment as soon as you suspect that you may have chickenpox.
As chickenpox is very contagious, it is advised to call and arrange your appointment to avoid waiting in the waiting room and potentially infecting other patients [3].
Treatment for chickenpox
The most common course of treatment is to manage the patient's symptoms and wait for the immune system to clear the virus.
In order to alleviate the itching, patients may be advised to take lukewarm baths, apply unscented lotion, wear lightweight soft clothing, and use over-the-counter antihistamines or topical ointments to help relieve the itching [4].
Paracetamol (acetaminophen) can be used to treat the fever if it presents. Patients are advised to not take aspirin, due to threat of Reye syndrome, which is a serious potential complication, particularly young children (under 6 years) [1].
In some cases, antiviral drugs may be prescribed such as acyclovir of valacyclovir to combat the virus, particularly when there's a risk of complications [5].
Chickenpox on black skin
Chickenpox, as well as other skin conditions, may appear differently on dark or black skin. Skin conditions can be harder to identify on black and brown skin. For example, a study found that medical students correctly identified hives on skin of color only 57.5% of the time, compared to 82.2% on white skin.
To accomplish good healthcare outcomes, these differences must be noted, studied and included into clinical practice.
The initial presentation of chickenpox on black skin are small bumps in the affected area. These may appear raised or slightly swollen. The skin on and around these bumps is typically discoloured compared to the surrounding skin. Depending on the individual's skin tone, they may appear purple, dark pink or dark brown [6].
As the chickenpox infection progresses, the rash or bumps progress to vesicles, which are fluid-filled sacs that form under the skin. These resemble blisters. Some people only have these vesicles scattered throughout the affected area, however, in some cases, the vesicles can merge and form an area that looks like a burn or a plaque. This can appear white or grey in colour. Meanwhile, the surrounding skin remains discoloured, appearing purple, pink or dark brown [6].
In rare cases, chickenpox in black patients presented with complications including varicella gangrenosa, which presents as painful necrotic (with dead tissue) lesions [7]. Another potential complication in black people is development of keloids after chickenpox [8]. Keloids are a type of scar which assume the shape of a growth or a tumour.
Challenges in diagnosing skin conditions on dark skin
Diagnosing skin conditions in patients with dark skin can present unique challenges to healthcare professionals due to the complexities of pigmentation and the way the pigment interacts with the clinical presentation of skin conditions [9]. This is particularly true in diseases where visual identification of symptoms on the skin is key to conclusively making a diagnosis [10].
Chickenpox
For chickenpox, the rash we described above may not be easily visible, potentially leading to misdiagnosis or late diagnosis [11]. In these cases, a potential improvement of the diagnostic pathway is to utilise a PCR test to detect the presence of the varicella-zoster virus [11].
Psoriasis
Psoriasis is a chronic inflammatory skin disease characterised by thickened, red, scaly plaques on the skin. In people with dark skin tones, the plaques are not red, however instead appear more blueish-purple, brown or grey [12].
Light sensitivity (Photodermatoses)
Photodermatoses is a collective term used to describe an excessive reaction to ultraviolet (UV) or visible light. It is believed that melanin, the dark skin pigment, facilitates protection against light. However, people with dark skin are not immune to photodermatoses; in fact, they are relatively common, however they do not present with visible reddening [13].
Summary
In conclusion, diagnosing skin conditions in patients with dark skin requires a keen understanding of the unique ways these conditions present in darker skin tones [10]. As for chickenpox, the bumps in the initial stages of the disease may appear smaller and dark purple, dark pink or dark brown in colour.