What is an acanthosis?
Acanthosis refers to the thickening of the prickle cell layer (also known as the stratum spinosum) in the epidermis, which is the outermost layer of the skin. It is a common histological finding seen in various skin conditions and diseases, and can be a result of different factors.
*Causes of acanthosis:*
- Chronic inflammation: Acanthosis can occur in response to chronic inflammation in the skin. Inflammatory processes, such as eczema, psoriasis, or lichen planus, can lead to increased proliferation and thickening of the prickle cell layer.
- Hyperproliferative disorders: Certain skin disorders characterized by abnormal growth and proliferation of skin cells can result in acanthosis. Examples include actinic keratosis, seborrheic keratosis, and certain types of skin cancer.
- Viral infections: Viral infections like human papillomavirus (HPV) and molluscum contagiosum can cause acanthosis as part of their pathological effects on the skin.
- Medication side effects: Some medications, such as certain chemotherapy drugs, can induce acanthosis as a side effect.
- Genetic disorders: Rare genetic disorders, such as Darier disease and Hailey-Hailey disease, are characterized by acanthosis as a primary feature.
Microscopic findings:
Acanthosis appears as a thickening of the prickle cell layer when examined under a microscope in a skin biopsy. It is characterized by:
- Increased number of cell layers: The prickle cell layer appears to have more layers of cells compared to normal skin.
- Elongated rete ridges: The rete ridges are the downward projections of the epidermis into the underlying dermis. They become elongated and thickened in acanthosis.
- Cellular changes: The prickle cells may show increased intercellular connections, prominent nucleoli, and occasionally cellular atypia depending on the underlying cause of acanthosis.
Treatment:
The treatment of acanthosis depends on the underlying cause and the specific skin condition it is associated with. Managing the primary disease or condition usually leads to improvement in acanthosis. Treatment approaches may involve topical or systemic medications, surgical interventions if needed, or lifestyle modifications to address any contributing factors.