1. Primary Cause
- Sarcoptes scabiei mites: Scabies is primarily caused by an infestation of tiny, eight-legged mites called Sarcoptes scabiei. These mites burrow into the top layer of human skin to live and feed, causing the characteristic symptoms of scabies.
2. Transmission
- Direct skin-to-skin contact: The most common method of transmission for scabies is direct skin-to-skin contact, including sexual contact.
- Infested furniture, clothes, and bedding: Though less common, scabies mites can also be spread through contact with infested items like furniture, clothes, and bedding.
Risk Factors
1. Demographic and environmental factors
- Close living conditions: Scabies เล่นบาคาร่า UFABET เว็บตรง ค่าคอมสูง outbreaks are common in institutional settings such as hospitals, boarding schools, long-term care facilities, and refugee or internally displaced person camps due to overcrowding and increased skin-to-skin contact.
- Age: Scabies can affect people of all ages, but it is most common in children and the elderly. Young children are at higher risk due to their close contact with others in daycare or school settings. The elderly are more susceptible due to weakened immune systems and the likelihood of living in long-term care facilities.
- Compromised immune system: Individuals with weakened immune systems, such as those with HIV/AIDS, cancer, or organ transplant recipients, are at higher risk for contracting scabies and developing crusted scabies.
2. Behavioral Factors
- Skin-to-skin contact: Direct skin contact with an infected person, especially if they have an itchy rash, significantly increases the risk of transmission. This includes sexual contact, holding hands, or sharing a bed.
- Sharing personal items: Scabies mites can survive for a short period on clothing, bedding, or towels. Sharing these items with an infested person increases the risk of contracting scabies.
Complications
Scabies can lead to several complications if left untreated or improperly managed:
- Secondary bacterial infections: Scabies can pave the way for secondary bacterial infections, particularly with Streptococcus pyogenes and Staphylococcus aureus. These infections can manifest as impetigo, cellulitis, and in severe cases, pyelonephritis, abscesses, pyogenic pneumonia, sepsis, and even death.
- Persistent itching and insomnia: Even after successful treatment, patients may experience persistent itching for 2-4 weeks due to the immune system’s reaction to dead mites and their products. This can lead to sleeplessness and may require additional treatments like antihistamines or topical steroids.
- Community outbreaks: Untreated or improperly treated scabies can spread rapidly within communities, especially in closed environments such as residential aged care facilities and schools, leading to outbreaks.
- Postscabietic reactions: Patients may experience reactions like Id reactions (auto-eczematisation) and epidermal changes due to topical treatments, which can prolong the recovery period.