What causes armpit herpes?

Many people may not know what causes armpit herpes. Because the sweat glands in the armpit area are more developed, more sweat is secreted, and there is armpit hair, it is easy for bacteria to be produced and herpes to develop. Herpes is mainly caused by viruses, some of which appear in the form of spots or flakes, and some appear in the form of bands. Let's take a closer look at what armpit herpes is.

1. Causes

Humans are the only host of the varicella-zoster virus. The virus enters the blood through the respiratory mucosa to form viremia, causing chickenpox or latent infection. The virus can then remain latent in the dorsal root ganglia of the spinal cord or the sensory ganglia of the cranial nerves for a long time. When the body is exposed to some kind of stimulus (such as trauma, fatigue, malignant tumors, or weakness after illness), which causes the body's resistance to decrease, the latent virus is activated and travels down the axons of the sensory nerves to the skin of the area innervated by the nerves, where it replicates and produces blisters. At the same time, the affected nerves become inflamed and necrotic, causing neuralgia. After recovery from this disease, more lasting immunity can be obtained, so it generally will not recur.

2. Clinical manifestations

1. Typical manifestations

Before the rash occurs, there may be systemic symptoms such as mild fatigue, low fever, and poor appetite. The affected skin will feel burning or neuralgia, and there will be obvious pain sensitivity when touched, which lasts for 1 to 3 days. The rash may also occur without any prodromal symptoms. The most common sites are the areas innervated by the intercostal nerves, cervical nerves, trigeminal nerves and lumbar sacral nerves. The affected area often first develops erythema, soon followed by millet- to soybean-sized papules, which are clustered and not fused, and then quickly turn into blisters with tense and shiny blister walls, clear blister fluid, and a red halo around the periphery. The skin between clusters of blisters is normal. The lesions are arranged in a band-like pattern along a peripheral nerve, mostly on one side of the body, usually not exceeding the midline. Neuralgia is one of the characteristics of this disease, which may occur before the onset of the disease or accompany skin lesions, and is often more severe in elderly patients. The course of the disease is generally 2 to 3 weeks. After the blisters dry up and the scabs fall off, temporary light red spots or pigmentation remain.

2. Special performance

(1) Herpes zoster ophthalmicus is caused by a virus that invades the ophthalmic branch of the trigeminal nerve. It is more common in the elderly and causes severe pain. It can also affect the cornea and cause ulcerative keratitis.

(2) Herpes zoster oticus is caused by a virus invading the facial nerve and auditory nerve, and manifests as herpes in the external auditory canal or tympanic membrane. When the geniculate ganglion is affected and the motor and sensory nerve fibers of the facial nerve are invaded at the same time, a triad of facial paralysis, ear pain, and external auditory canal herpes may occur, which is called Ramsay-Hunt syndrome.

(3) Postherpetic neuralgia: Herpes zoster is often accompanied by neuralgia, which can occur before the rash, during the rash, and after the skin lesions have healed. However, it usually disappears after the skin lesions have completely subsided or within 1 month. In a few patients, the neuralgia may last for more than 1 month, which is called postherpetic neuralgia.

(4) Other atypical herpes zoster are related to the differences in the body's resistance of patients, and can manifest as abortive type (no skin lesions, only neuralgia), incomplete type (only erythema and papules appear without blisters and then disappear), bullous type, hemorrhagic type, gangrenous type and generalized type (simultaneous involvement of more than two ganglia, resulting in skin lesions in multiple areas on the contralateral or ipsilateral side). The virus can occasionally spread through the blood to produce widespread varicella-like rash and invade organs such as the lungs and brain, which is called disseminated herpes zoster.

4. Diagnosis

1. Clusters of blisters appear on the affected skin, distributed in a band-like pattern along the peripheral nerves on one side.

2. There is obvious neuralgia, accompanied by local lymphadenopathy.

3. The skin in the middle is normal.