Scabies: From Recognition to Management

Welcome back, DERM Community!

Last week, we explored abscesses, breaking down their causes, treatment, and prevention, and reminding ourselves why timely action matters.

This week, we’re turning our focus to scabies, a parasitic skin infestation that is often underestimated, underdiagnosed, and undertreated.

Despite being a global health issue, scabies is frequently mistaken for eczema, dermatitis, or allergies,  delaying proper care.

Here’s why this topic deserves your clinical attention:

• Highly contagious: Spread by close skin-to-skin contact, sometimes household-wide.

• Easily misdiagnosed: Mimics other itchy dermatoses, especially atopic dermatitis.

• Treatment requires precision: Topical vs. oral therapies, environmental decontamination, and patient education all matter.
  

Let’s dive into the essentials every clinician should know.

Featured on This Week’s Chapter:

Scabies — Clinical Essentials

• What It Is → The mite, its life cycle, and how infestation develops.

• Diagnosis in Practice → Key symptoms, exam findings, and common diagnostic pitfalls.

• Treatment Strategies → Permethrin, ivermectin, and environmental control.

• Clinical Benefits → Why recognizing scabies early reduces suffering and prevents outbreaks.

• Dermatology News You Can Use → New updates on parasitic skin diseases.

• Book Recommendation → A must-read for honing diagnostic thinking.

Scabies: What You Need to Know

Scabies is a contagious skin condition caused by the mite Sarcoptes scabiei var. hominis. The mites burrow into the skin, triggering an intense immune-mediated itch that worsens at night.

Classic Signs & Symptoms:

• Severe nocturnal pruritus.

• Burrows: thin, wavy, gray-white lines on wrists, interdigital spaces, axillae, waist, and genitals.

• Papules, nodules, and secondary eczematization due to scratching.
  

Complications:

• Secondary bacterial infections (impetigo, cellulitis).

Crusted scabies in immunocompromised patients: highly contagious, difficult to treat, and associated with increased morbidity.

Diagnosis: Key Clinical Pearls

• High suspicion in patients with widespread itching + family members with similar symptoms.

• Dermoscopy or skin scrapings can reveal mites, eggs, or fecal pellets, but absence doesn’t exclude diagnosis.

• Don’t confuse it with eczema flares; distribution and nocturnal itch are important differentiators.

Prevention & Public Health Impact

• Early recognition prevents outbreaks in families, nursing homes, schools, and communities.

• Patient education is key: Reinforce the importance of treating all contacts, not just the symptomatic patient.

Clinical Pearls

• Always ask about itching in household contacts.

• Treat all close contacts at the same time, even if asymptomatic.

• Reassure patients that post-treatment itch can persist for weeks (“post-scabetic itch”) and does not always mean treatment failure.

• Don’t forget crusted scabies: it requires aggressive multi-dose therapy and strict infection control.

We’ve Put Together a Free Guide Just for You!

Key Reads for Your Practice

1. Scabies: Current Knowledge and Future Directions

This comprehensive review highlights the global burden of scabies, the challenges of diagnosis, and the growing momentum behind mass drug administration strategies for control. A must-read for clinicians interested in both the bedside and the public health perspective.

Read here: https://www.frontiersin.org/journals/tropical-diseases/articles/10.3389/fitd.2024.1429266/full

2. Post-scabies itch: an overview of causes and treatment strategies

This article explores why intense itching often continues even after successful eradication of the mites. It discusses immunological mechanisms, patient case studies, timelines for symptom persistence, and treatment strategies including topical steroids, antihistamines, and patient counseling.

Read here: https://pubmed.ncbi.nlm.nih.gov/38175616/ 

Book Recommendation of the Week

The Checklist Manifesto: How to Get Things Right by Atul Gawande

Scabies management often falters not because the treatment doesn’t work, but because critical steps (treating contacts, decontaminating the environment) are overlooked.

Inspiration of the Week

👋🏻 See you next Thursday, DERM community!

This week, we shed light on scabies, a condition easy to miss but essential to treat well.

Next month is Eczema Awareness Month!  We’ll dedicate several issues to unpacking eczema: from skin barrier dysfunction to the microbiome and the latest therapeutic insights.

If today’s chapter sharpened your perspective on scabies, share it with colleagues or trainees: awareness leads to better patient care.

Thank you for being here with us!

— The Derm for Primary Care Team