Mollaret’s Meningitis

Mollaret's Meningitis


The best part of working in the Emergency Department at Carolinas Medical Center is being surrounded by so many brilliant colleagues.  I learn something new every shift (and, in truth, is where the majority of these Morsels are baked).  Today’s Morsel is a reflection of that fact.

We evaluate headache often.  With the mantra of “worst first” echoing in our ears we naturally consider meningitis, but, fortunately, we are often able to exclude it based on our exam.  In previous Morsels, we have discussed concerning characteristics of headaches as well as some interesting causes of headaches (AVM, meningococcemia, pseudotumor).  What if, however, the patient has had viral meningitis previously?  What is Mollaret’s Meningitis anyway?


Recurrent Meningitis

Can be separated into two main categories:

  • Recurrent Bacterial Meningitis

    • Bacterial meningitis untreated is almost always fatal.
    • Recurrence implies that it was treated, but there is an underlying cause for the bacteria to gain access to the CSF again. Examples:
      • Congenital middle ear abnormalities
      • Persistent dermal sinus along the spinal column
      • Basilar skull fractures
      • Sinusitis, Mastoiditis, Deep Space Abscess
      • Immunodeficiencies


  • Recurrent Non-purulent Meningitis

    • Recurrent non-purulent meningitis can be due to a wide variety of entities including infectious as well as non-infectious causes.
    • Infectious
      • Bacteria, spirochetes, fungi, protozoa, viruses.
    • Non-Infectious
      • Tumors (ex, epidermoid cysts and craniopharyngioma)
      • Inflammatory Conditions (ex, Sacroid, Systemic Lupus Erythematosus)
      • Drugs (drugs can always cause badness)


Mollaret’s Meningitis

  • In 1944, Pierre Mollaret first described Recurrent Benign Lymphocytic Meningits due to HSV-2.
  • Recurrent (at least 3 episodes), benign and brief (usually 2-5 days) episodes of aseptic lymphocytic meningitis.
  • Lymphocytes have characteristic appearances:
    • Large activated monocytes with several deep clefts in the nuceli called:
      • “Cloverleaf nucleus,” “Footprint-shaped nucleus,” “bean-shaped nucleus.”
      • Also referred to as “Mollaret’s cells.”
    • These cells are most likely present in the first 24 hours of the illness.
  • Onset of disease has been observed from 5 years to 83 years of age. Mean is 35 years of age.


Mollaret’s Meningitis Causes

  • Most cases are due to Herpes Simplex Virus type 2 (HSV-2).
  • HSV-1 and Human herpesvirus 6 (HHV-6) have also been associated.
  • It is a good idea to ask about recent herpes lesion outbreaks in your patients with headaches.


Mollaret’s Meningitis Treatment

  • This is a benign and self-limited disease, so does not officially require therapy.
  • Intravenous acyclovir is often used initially, while diagnosis is being clarified.
    • 10 mg/kg three times a day for 7-10 days.
  • Intermittent or continuous prophylaxis has also been used with the goal of preventing the recurrence.



Min Z1, Baddley JW2. Mollaret’s meningitis. Lancet Infect Dis. 2014 Oct;14(10):1022. PMID: 25253408. [PubMed] [Read by QxMD]
Poulikakos PJ1, Sergi EE, Margaritis AS, Kioumourtzis AG, Kanellopoulos GD, Mallios PK, Dimitrakis DJ, Poulikakos DJ, Aspiotis AA, Deliousis AD, Flevaris CP, Zacharof AK. A case of recurrent benign lymphocytic (Mollaret’s) meningitis and review of the literature. J Infect Public Health. 2010 Dec;3(4):192-5. PMID: 21126724. [PubMed] [Read by QxMD]

Abu Khattab M1, Al Soub H, Al Maslamani M, Al Khuwaiter J, El Deeb Y. Herpes simplex virus type 2 (Mollaret’s) meningitis: a case report. Int J Infect Dis. 2009 Nov;13(6):e476-9. PMID: 19329344. [PubMed] [Read by QxMD]

Davis LE. Acute and recurrent viral meningitis. Curr Treat Options Neurol. 2008 May;10(3):168-77. PMID: 18579020. [PubMed] [Read by QxMD]

Capouya JD1, Berman DM, Dumois JA. Mollaret’s meningitis due to human herpesvirus 6 in an adolescent. Clin Pediatr (Phila). 2006 Nov;45(9):861-3. PMID: 17041177. [PubMed] [Read by QxMD]


Sean M. Fox
Sean M. Fox
Articles: 583


  1. I didn’t know you were at Carolinas Medical Center! I am just up the road in Winston-Salem. I really enjoy the work you do with these morsels. I work at a community hospital, Thomasville Medical Center. Single MD coverage with several mid-levels. We see about 36,000 patients per year and weird pediatric pathology walks, or is carried, through the door way more frequently than you might imagine. Your emails really help me in my practice. Thank you!

    Mike Capriola

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