Hand, foot, and mouth disease is an acute, self-limiting viral illness caused by non-polio enteroviruses, most commonly coxsackievirus A16 and enterovirus 71. After an incubation of 3-6 days, patients develop fever, anorexia and sore throat, followed within 24-48h by painful oral ulcers and a vesiculopapular rash on the palms, soles, buttocks or genitals. Lesions are 2-8 mm greyish vesicles on an erythematous base, often arranged linearly along skin lines. The eruption is symmetrical, transient and heals without scarring in 7-10 days. Variants due to coxsackievirus A6 may produce larger bullae or diffuse involvement mimicking varicella.
What causes HFMD and how does it spread?
The virus replicates in the pharynx and intestine, enters the bloodstream and seeds the skin and mucosa. Transmission occurs via respiratory droplets, saliva, vesicle fluid and faeces, with peak viral shedding during the first week of illness. Outbreaks peak in late summer and autumn, predominantly affecting children under 5 years but increasingly reported in adults. Close-contact settings such as day-care centres and schools facilitate rapid dissemination.
How is HFMD classified?
Clinically, HFMD is divided into:
1. Uncomplicated HFMD–fever, oral ulcers and typical acral rash without systemic features.
2. Complicated HFMD–encephalitis, aseptic meningitis, acute flaccid paralysis, myocarditis or pulmonary oedema, almost always linked to enterovirus 71.
3. Atypical HFMD–widespread bullous lesions, purpuric or haemorrhagic morphology, caused by coxsackievirus A6 or A10.
How is HFMD diagnosed?
Diagnosis is clinical. A brief inspection of the mouth, hands, feet and buttocks is usually sufficient. A throat swab or stool sample may be sent for RT-PCR to identify the serotype in severe or atypical cases. Dermoscopy can assist in doubtful presentations: vesicles show central grey lacunae surrounded by a pale halo and radially arranged vessels, while oral ulcers display fibrin-covered yellow bases with surrounding erythema. These dermoscopic patterns are not pathognomonic but help differentiate HFMD from erythema multiforme, bullous impetigo or drug eruptions.
How to use the IBOOLO dermatoscope correctly?
Before using the IBOOLO dermatoscope, gently clean the lesion to remove any cosmetics or sunscreen that could interfere with the view. Next, place the device flat against the skin and adjust the focus until the image is sharp. If you need to capture photographs, attach the supplied phone clip to the phone’s main camera and magnetically connect the dermatoscope. Open the phone’s camera app and save the images to monitor the patient’s recovery.
The examination usually takes only a few minutes. Afterward, please clean the dermatoscope lens with alcohol to prevent cross-infection between patients. Of course, the IBOOLO dermatoscope disposable contact plate is now available, which can be discarded after use, making it more convenient and eliminating the need for disinfection of the dermatoscope.
What improvements has the IBOOLO DE-500 made?
The DE-500 offers three observation modes—polarized, non-polarized, and UV—and provides three brightness levels. These features were not fully present in any previous IBOOLO pocket dermatoscope, so the DE-500 offers a comprehensive set of functions that can rival those of IBOOLO handheld dermatoscopes. Non-polarized light is primarily used to examine the texture and details of the skin's surface, focusing on the epidermal layer; polarized light eliminates stray light, allowing users to clearly observe the condition of the dermal layer; 365nm UV light is used to detect fungal skin lesions and pigmentary disorders such as vitiligo and psoriasis. The three-level brightness adjustment function is designed to adapt to different ambient light conditions. Users can adjust the dermatoscope to different light intensities based on the ambient light conditions to achieve the best observation results.
And IBOOLO DE-500 connects magnetically, which is more convenient than the DE-400’s threaded attachment. The lens is produced with etched-glass technology, delivering sharper and more durable optics than the DE-400’s silk-screen process. Furthermore, the DE-500 uses the same Japanese-imported lens that will debut in our upcoming DE-5100, ensuring superior image quality.
How is HFMD treated?
There is no specific antiviral therapy. Management is supportive:
- Antipyretics (paracetamol or ibuprofen) for fever and pain.
- Topical oral anaesthetics (benzydamine rinse, lidocaine gel) for mouth ulcers.
- Cold soft diet and adequate hydration to prevent dehydration.
- In severe EV-71 disease, ICU care with mechanical ventilation, mannitol, dexamethasone, intravenous immunoglobulin and inotropes is indicated; mortality remains <2 % with prompt supportive care.
Secondary bacterial infection is uncommon; antibiotics are reserved for documented superinfection.
How can HFMD be prevented?
- Frequent hand-washing with soap and water, especially after diaper changes.
- Disinfection of toys, doorknobs and common surfaces.
- Exclusion of symptomatic children from school until fever resolves and oral ulcers have crusted.
- No licensed vaccine is widely available for coxsackievirus A16; EV-71 vaccines are used in selected Asian countries.