PATHCHAT Edition No. 70
August 2020
Please contact your local Ampath pathologist for more information.
Author:
- Dr. Shaun Naicker (Anatomical Pathologist)
Introduction
✅ Background on COVID-19 and Cutaneous Manifestations
- SARS-CoV-2 was first identified in Wuhan, China, in December 2019.
- The virus spread globally, leading to the WHO declaring a pandemic in March 2020.
- More than 23 million people were infected worldwide at the time of this report, with over half a million cases in South Africa.
- Complications include multi-organ dysfunction, progressive respiratory failure, and generalised coagulopathy, contributing to high mortality.
📌 Cutaneous manifestations are frequently observed in viral illnesses, and the sudden onset of a skin rash may indicate COVID-19 infection.
Prevalence of Cutaneous Manifestations in COVID-19
✅ Studies on Skin Manifestations in COVID-19 Patients:
- Italian Cohort: 20.4% (18/88) of patients developed cutaneous abnormalities.
- Chinese Cohort: 1.8% (2/1,099) presented with skin manifestations.
- UK Study: 8.8% of 336,000 participants listed skin rash as a symptom.
- Italian Ward Study: 20% (375/1,875) of COVID-19 patients had cutaneous lesions.
📌 Recognizing COVID-19-related skin conditions can aid in early diagnosis and management.
Classification of COVID-19-Associated Skin Lesions
✅ 1. Urticarial Lesions (19% of Cases)
- Commonly found on the trunk and limbs.
- May occur in the prodromal stage of infection.
- Associated with circulating immune complexes or urticarial vasculitis.
- Not linked to disease severity.
✅ 2. Maculopapular Lesions (47% of Cases)
- May resemble drug eruptions, viral exanthems, or pityriasis rosea.
- Perifollicular distribution and scaling observed in some cases.
- May be erythema multiforme-like.
- Associated with more severe COVID-19.
✅ 3. Papulovesicular Eruptions (9% of Cases)
- Varicella-like vesiculobullous eruptions.
- Small, monomorphic vesicles located on the trunk.
- Different from polymorphic vesicles seen in chickenpox.
- Duration of rash: ~10 days.
- Associated with intermediate disease severity.
✅ 4. Purpuric Eruptions
- Due to vascular invasion by the virus or disseminated intravascular coagulation (DIC).
- Reddish-brown lesions, often on the limbs.
- High morbidity and mortality rates.
✅ 5. Livedo Reticularis (6% of Cases)
- Mottled, lace-like purplish discoloration of the skin.
- Associated with microthrombosis and vascular damage.
- May be unilateral.
- Linked to severe disease and coagulopathy.
✅ 6. Thrombotic Ischaemic Lesions (19% of Cases)
- Pseudo-chilblain lesions ("COVID toes" and "COVID fingers").
- Asymmetrical erythema and oedema, sometimes with vesicles or pustules.
- May be due to microthrombi and endothelial damage.
- Usually affects younger patients and lasts approximately 12 days.
- Associated with less severe disease.
✅ 7. Vasculitis
- Leukocytoclastic vasculitis, causing inflammation of small blood vessels.
- Red spots on feet, ankles, lower legs, thighs, and trunk.
- Can be caused by viral infections like COVID-19 or medications.
📌 COVID-19-related skin manifestations range from mild to severe and may indicate underlying vascular complications.
Drug-Induced Cutaneous Reactions in COVID-19 Patients
✅ 1. Chloroquine & Hydroxychloroquine
- Urticaria, pruritus, Stevens-Johnson Syndrome (SJS)-like reactions.
- Psoriasiform dermatitis, alopecia, dry skin.
✅ 2. Azithromycin
- Morbilliform drug eruptions, angioedema.
- Leukocytoclastic vasculitis, DRESS syndrome, AGEP, SJS.
✅ 3. Remdesivir
- Maculopapular rash.
- Subcutaneous abscesses and thrombophlebitis at infusion site.
✅ 4. Tocilizumab
- Papulopustular eruptions, psoriasiform dermatitis.
- SJS-like reactions.
✅ 5. Lopinavir/Ritonavir & Other Antiretrovirals
- Maculopapular drug eruptions.
- Stevens-Johnson Syndrome (SJS) or toxic epidermal necrolysis (TEN).
- Lichenoid drug eruptions.
✅ 6. COVID-19 Vaccines
- Urticaria, scleroderma-like reactions.
- Maculopapular rashes, injection site reactions.
📌 Many drugs used to treat COVID-19 can also cause skin reactions, complicating diagnosis.
Time Course and Clinical Relevance of Skin Lesions
✅ Early-Onset Lesions (Within a Few Days of Symptoms Onset):
- Urticarial lesions (19% of cases).
- Maculopapular rashes (47% of cases).
- Papulovesicular (varicella-like) eruptions (9% of cases).
✅ Late-Onset Lesions (Appearing Later in the Disease Course):
- Purpuric eruptions.
- Livedo reticularis (6% of cases).
- Thrombotic ischaemic lesions (19% of cases).
📌 Certain skin lesions correlate with disease severity, with purpuric and livedoid lesions being associated with high mortality.
Key Takeaways for Clinicians
✅ Skin manifestations can be an early sign of COVID-19 infection.
✅ Maculopapular eruptions are the most common COVID-19-related rash.
✅ Vascular-related lesions (livedo reticularis, thrombotic ischaemia) indicate severe disease.
✅ Drug-induced reactions must be differentiated from true COVID-19 cutaneous manifestations.
✅ Identifying skin changes may aid in the early detection and management of COVID-19 patients.
📌 Clinicians should consider COVID-19 in patients presenting with sudden unexplained skin rashes, especially in the presence of fever or respiratory symptoms.