My patient with history of intravenous drug use has noticed excessive growth of thick hair at the site of a previous abscess on her arm. Is there a connection between skin and soft tissue infections and localized hypertrichosis?

Localized hypertrichosis after infectious rash or “HAIR”, has been reported following a variety of skin and soft tissue infections (SSTIs), including sites of previous septic thrombophlebitis, cellulitis and olecranon bursitis. 1,2  A similar phenomenon has also been described in infants with recent chicken pox, as well non-infectious skin conditions arising from repeated irritation, friction, burns, excoriated insect bites, and fractures with cast application.1,2

Although heat and hyperemia have been implicated as growth stimulants for the hair follicle, 3 the exact mechanism of this intriguing phenomenon is unclear. It is possible that the sustained inflammatory process associated with chronic or more severe SSTIs leads to protracted stimulation of certain growth receptors in the human hair follicles (eg, transient vanilloid receptor-1) through heat and inflammation, as observed in mice in vivo.4

Aside from its possibly undesirable esthetic effects, localized HAIR appears to have no adverse health consequences, is reversible, and should require no further evaluation.

Note: 2 of the publications cited were written by the author of this post.

References

  1. Manian, FA. Localized hypertrichosis after infectious rash in adults. JAAD Case Reports 2015; 1:106-7. https://www.jaadcasereports.org/article/S2352-5126(15)00051-X/pdf
  2. Manian, FA. Localized hypertrichosis after infectious rash (“HAIR”) in adults: a report of 5 cases. Open Forum Infect Dis 2014;1 (Suppl 1):S195-S195. http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC5782143&blobtype=pdf
  3. Leung AK, Kiefer GN. Localized acquired hypertrichosis associated with fracture and cast application. J Natl Med Assoc 1989;81:65-7. https://www.ncbi.nlm.nih.gov/pubmed/2724357
  4. Bodo E, Biro T, Telek A, et al. A hot new twist to hair biology; involvement of vanilloid receptor-1 (VR1/TRPV1) signaling in human hair growth control. Am J Pathol 1005;166:985-8. https://www.sciencedirect.com/science/article/pii/S0002944010623206

 

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My patient with history of intravenous drug use has noticed excessive growth of thick hair at the site of a previous abscess on her arm. Is there a connection between skin and soft tissue infections and localized hypertrichosis?

Why is there a predilection for the tricuspid valve (TV) infection among injection drug users (IDUs) with infective endocarditis (IE)?

Although right-sided IE accounts for only 9% of IE cases among non IDUs, in IDUs it accounts for over three-quarters of IE cases1.  

Several potential mechanisms have been posited to explain susceptibility of TV to infection in IDUs, including endothelial damage due to repeated inoculation of small bacterial loads, specific substances (eg talc) injected with drugs,  cocaine-induced vasospasm and thrombus formation, and drug-induced pulmonary hypertension associated with increased pressure gradients and turbulence.  In addition, facilitation of bacterial adhesion due to the deposition of immune complexes (eg antibody vs antigens in injected drugs) on the TV and coating of the injected particulate matter with bacterial adherence matrix molecules on valve surfaces may also play an important role1,2.

Add to these potential factors a higher risk nasal and cutaneous colonization with Staphylococcus aureus (a common cause of IE) among IDUs, and we have a perfect storm!

References

  1. Frontera JA, Gradon JD. Right-sided endocarditis in injection drug users: review of proposed mechanisms of pathogenesis. Clin Infect Dis 2000;30:374-9.
  2. Chahood J, Yakan AS, Saad H, et al. Right-sided infective endocarditis and pulmonary infiltrates: An update. Cardiol Rev 2016;24:230-37.
Why is there a predilection for the tricuspid valve (TV) infection among injection drug users (IDUs) with infective endocarditis (IE)?

When should I seriously consider active tuberculosis (TB) in my newly-admitted HIV-negative patient with a cough?

Active TB should be suspected based on a combination of epidemiological (eg, exposure, travel to, or residence in a high prevalence area, history of prior TB), clinical (eg, cough lasting 2-3 weeks or longer, fever, night sweats, weight loss, fatigue, less commonly, chest pain, dyspnea, and hemoptysis), chest radiograph abnormalities (eg, infiltrates, fibrosis, cavitation), and histopathologic (eg, caseating granuloma)1.

Among HIV-negative patients, the highest prevalence of TB is found those who have been incarcerated, use intravenous drugs, have alcohol use disorder, or are immunocompromised (including diabetes mellitus)2,3

Patients suspected of TB based on clinical criteria should undergo chest radiography.  Reactivation pulmonary TB (~90% of TB in adults) classically presents with upper lobe and/or the superior segment of the lower lobe disease.  Remember that up to 5% of patients with active pulmonary TB have normal chest radiograph, however4.  

All hospitalized patients suspected of having active TB should be placed on appropriate isolation precautions.

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References

  1. Sia IG, Wieland ML. Current concepts in the management of tuberculosis. Mayo Clin Proc. 2011;86:348-361. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3068897/
  2. Center for Disease Control. Tuberculosis: Data and Statistics. https://www.cdc.gov/tb/statistics/default.htm. Accessed October 3, 2016.
  3. World Health Organization. Tuberculosis. http://www.who.int/mediacentre/ factsheets/fs104/en/. Accessed October 3, 2016.
  4. Marciniuk, D, McNab, BD, Martin WT, Hoeppner, VH. Detection of pulmonary tuberculosis in patients with a normal chest radiograph. Chest 1999;115:445-452. https://journal.chestnet.org/article/S0012-3692(15)50590-4/abstract

 

 

Contributed by Charles C. Jain MD, Medical Resident, Massachusetts General Hospital

 

When should I seriously consider active tuberculosis (TB) in my newly-admitted HIV-negative patient with a cough?