Sandbox:Ifeoma Anaya
| Febrile Rash | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Infectious | Non-infectious | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
There are several types of skin rashes classified based on size, consistency, color, etc. Below are some of the common ones encountered in clinical practice.
| Type of Rash/Lesion | Description |
|---|---|
| Macule | flat, circumscribed, usually <1cm in diameter |
| Papule | raised/elevated lesion <1cm in diameter |
| Maculopapular | combination of both macules and papulus |
| Nodule | papule in deeper dermis or subcutaneous tissue |
| Pustule | circumscribed raised lesion containing purulent material |
| Vesicle | circumscribed elevated skin lesion usually <1cm containing fluid |
| Bulla | Bigger vesicle (>1cm and containing fluid) |
| Purpura | non-blanching papules or macules due to extravasation of RBCs |
| Petechiae | non-blanching pinpoint unraised spots usually measuring <2mm in size |
Synonyms and keywords: Exanthema subitum; sixth disease; roseola infantilis; baby measles; three-day fever; rose rash of infants
Roseola Infantum
Overview
Historical Perspective
Previously known as "Roseola infantilis", the oldest known description of the disease dates as far back as 100 years ago by John Zahorsky, M.D in his publication in 1913 . Described as a symptom-complex of febrille erythema occuring in infants and not to be categorized alongside the erythema group of skin diseases. However, no clear-cut description was given to differentiate it from other pediatric skin eruptions [1]. While the disease has been recognized for almost a century, Human Herpes Virus type 6 (HHV-6) was discovered in 1986 .
Pathophysiology
Mode of transmission is still not fully understood however it has been speculated that it is primarily via saliva and commonest form of transmission is from mother to child . Viral replication occur mostly in CD4+ T cells and incubation period is between 9-10 days [2]. High levels of Metalloproteinase 9 and Tissue Inhibitor of Metalloproteinase 1 has been shown to disrupt the blood-brain barrier and thus, the cause of the febrille seizures observed in some infants infected with the virus . More severe disease pathology can be seen in the immunocompromised because it remains latent in the lymphocytes and monocytes after primary infection .
Causes
Disease is caused by HHV-6 and less commonly by HHV-7 which are members of the Herpesviridae family [2]. HHV-6 has a linear, double-stranded DNA genome [2]. The HHV-6 has its primary variant, HHV-6B which is the associated with Roseola infantum while the other variant, HHV-6A has not been associated with any disease(s) [2].
Epidemiology and Demographics
Children are the most commonly infected. Newborns have passive antibodies to HHV-6 passed on to them from their mother which wanes by 4-6 months . By 12 months of age, incidence of the disease is about 40%, this increases to 77% by 24 months [3]. Primary infection peaks between 9-21 months of age [3].
Natural History, Complications and Prognosis
Classical finding of Roseola infantum is very high fever which can be higher than 39°C [2]. This fever lasts for 3-5 days and can be accompanied by other symptoms like malaise, conjuctivitis, inflammed tympanum, anorexia, irritability, lymphadenopathy, cough, etc [2]. On sudden disappearance of the fever (3-5 days later), small, rose-pink, non-pruritic, blanching, maculopapular rashes appear first on the trunk and then spreads to the neck, face and extremities [2]. This usually lasts 1-2 days and ends the infection period [2].
Complications seen during primary infection include febrille seizures, rhabdomyolysis, myocarditis, Guillain-Barre Syndrome [2]. Limbic encephalitis seen in immunocompromised individuals post stem cell transplantation is an established long-term complication as a result of reactivation of HHV-6B virus [3].
Roseola infantum is a self limiting infection with very good prognosis and few complications [2].
Diagnosis
This is basically clinical. A well taken history and physical exam gives away the diagnosis of Roseola infantum and differentiates it from other viral exanthems.
Treatment
Usually supportive with antipyretics for fever and general discomfort, continued fluid intake to replace insensible losses from high temperatures, and rest. There is currently no vaccine for HHV-6 and no antiviral treatment for primary infection [2].
Prevention
Hand washing is encouraged to prevent spread [2].
Differentiating Roseola Infantum from other Diseases
| classification | ||||
|---|---|---|---|---|
| SCC | ||||
| BCC | ||||
| Melanoma | ||||
Practice here
| Criteria | Symptomatic WM | Asymptomatic WM | IgM-Related Disorders | MGUS |
|---|---|---|---|---|
| IgM monoclonal protein | + | + | + | + |
| Bone marrow infiltration | + | + | - | - |
| Symptoms attributable to IgM | + | - | + | - |
| Symptoms attributable to tumor infiltration | + | - | - | - |
|
Bowen's disease Microchapters |
References
- ↑ Zahorsky, John (1913). "ROSEOLA INFANTUM". JAMA: The Journal of the American Medical Association. 61 (16): 1446. doi:10.1001/jama.1913.04350170028008. ISSN 0098-7484.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 "StatPearls". 2020. PMID 28846307.
- ↑ 3.0 3.1 3.2 Tesini BL, Epstein LG, Caserta MT (2014). "Clinical impact of primary infection with roseoloviruses". Curr Opin Virol. 9: 91–6. doi:10.1016/j.coviro.2014.09.013. PMC 4267952. PMID 25462439.