History

Fact Explanation
Itching Tungiasis is a skin infestation caused by a burrowing flea. The causative flea is called Tunga penetrans/ chigoe flea/ jigger. The skin is infested by the adult through a bite on the surface. Then it burrows through the skin in to the epidermis to be fed from blood vessels in the upper dermis. The most common infestation site is the feet. Most individuals may asymptomatic. Some develops an itching as the initial presenting complaint. The affected area in usually red and warm due to the inflammation. [1,2,3,4,5]
Skin lesion Some patients develop papules and nodules in the site. These papules/ nodules have sharp point or tip with a black dot on them (punctum). Usually they are extremely painful and itchy. [2,3,4]
Ulcer Itching on the nodules/ papules cause ulcerations on the site. [1,3,4]
Complications Secondary bacterial infections, including tetanus and gangrene are common in tungiasis. [2,4,5]
At risk population Tungiasis is more common in Caribbean region, Africa, India ,Pakistan and Latin America. People who walk on bare foot in dry soil and sandy beaches, stables and farms are at higher risk. [1,3,5]
References
  1. JACKSON A, STEVENSON L, COGGESHALL P, WHITMAN TJ. A patient returning from Africa finds a mass imbedded in the skin of her right foot. Tungiasis. Clin Infect Dis [online] 2012 Nov, 55(9):1227, 1273-4 [viewed 21 August 2014] Available from: doi:10.1093/cid/cis607
  2. WINTER B, OLIVEIRA FA, WILCKE T, HEUKELBACH J, FELDMEIER H. Tungiasis-related knowledge and treatment practices in two endemic communities in northeast Brazil. J Infect Dev Ctries [online] 2009 Jul 1, 3(6):458-66 [viewed 21 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/19762960
  3. MAZIGO HD, BEHAMANA E, ZINGA M, HEUKELBACH J. Tungiasis infestation in Tanzania. J Infect Dev Ctries [online] 2010 Mar 29, 4(3):187-9 [viewed 21 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/20351463
  4. MACO V, TANTALEáN M, GOTUZZO E. Evidence of tungiasis in pre-Hispanic America. Emerg Infect Dis [online] 2011 May, 17(5):855-62 [viewed 21 August 2014] Available from: doi:10.3201/eid1705.100542
  5. CRIADO PR, LANDMAN G, REIS VM, BELDA W JR. Tungiasis under dermoscopy: in vivo and ex vivo examination of the cutaneous infestation due to Tunga penetrans. An Bras Dermatol [online] 2013 Jul-Aug, 88(4):649-51 [viewed 21 August 2014] Available from: doi:10.1590/abd1806-4841.20132071

Examination

Fact Explanation
Skin lesion Patients may present with extremely itchy, erythematous skin in the parts of the feet. After that stage they may develop papules/ nodules which has a punctum. The lesion can range from 4-10mm in diameter. Some may develop ulcerations afterwards. [1,2,3]
Difficulty in walking Multiple lesions in the feet can lead to difficulty in walking. [1,2]
Bacterial infections This can occur over the scratch marks of the area or in the ulcer. [2,3]
References
  1. JACKSON A, STEVENSON L, COGGESHALL P, WHITMAN TJ. A patient returning from Africa finds a mass imbedded in the skin of her right foot. Tungiasis. Clin Infect Dis [online] 2012 Nov, 55(9):1227, 1273-4 [viewed 21 August 2014] Available from: doi:10.1093/cid/cis607
  2. WINTER B, OLIVEIRA FA, WILCKE T, HEUKELBACH J, FELDMEIER H. Tungiasis-related knowledge and treatment practices in two endemic communities in northeast Brazil. J Infect Dev Ctries [online] 2009 Jul 1, 3(6):458-66 [viewed 21 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/19762960
  3. MACO V, TANTALEáN M, GOTUZZO E. Evidence of tungiasis in pre-Hispanic America. Emerg Infect Dis [online] 2011 May, 17(5):855-62 [viewed 21 August 2014] Available from: doi:10.3201/eid1705.100542

Differential Diagnoses

Fact Explanation
Cercarial dermatitis Cercarial dermatitis, also known as swimmer's itch, is an itchy allergic reaction caused by larvae of Schistosoma cercariae parasites in class trematoda that enter the skin. Swimmer's itch develops on exposed areas of the skin after contact with these larval forms when they mistakenly penetrate the person's skin rather than its usual host, a duck. The rash does not occur following the initial contact. Repetitive exposure develop a stronger hypersensitivity reaction. Initial itchy or tingling sensation usually settles quickly, leaving the infected individual with tiny red spots at the sites of larvae penetration. After several hours those red spots develop into papules (raised bumps) or hives (a rash of round, red , itchy weals). Within the next 1-2 days they blisters (a small bubble on the skin filled with watery liquid) develop which may spontaneously resolves with time. [1]
Insect bites Insect bites and stings can be simply divided into 2 groups: venomous and non-venomous. For most people, insect bites or stings cause a mild reaction. Venomous stings usually cause a stinging sensation or pain with redness and swelling of the area. Itch is usually not a concern. In some people who are sensitive to insect venom, a sting may cause a severe allergic reaction known as anaphylaxis. This results in facial swelling, difficultly breathing and an itchy rash (urticaria) over most of the body. This can be life-threatening so immediate medical attention and treatment needs to be sought. [2]
Sea bather's eruption Sea bather's eruption is a rash that affects areas of the skin covered by a bathing suit, rather than exposed areas, after swimming in the sea. It is caused by stings from the stinging cells (also called nematocysts) of the larval forms of certain sea anemones and thimble jellyfishes. A tingling sensation under the bathing suit (breasts, groin, cuffs of wetsuits) is often first noticed while still in the water. Over several hours it becomes an itch, which can last for several weeks. [3]
References
  1. FARAHNAK A, ESSALAT M. A study on cercarial dermatitis in Khuzestan province, south western Iran. BMC Public Health [online] 2003 Nov 7:35 [viewed 26 July 2014] Available from: doi:10.1186/1471-2458-3-35
  2. SINGH S, MANN BK. Insect bite reactions. Indian J Dermatol Venereol Leprol [online] 2013 Mar-Apr, 79(2):151-64 [viewed 21 August 2014] Available from: doi:10.4103/0378-6323.107629
  3. BRANT SV, COHEN AN, JAMES D, HUI L, HOM A, LOKER ES. Cercarial dermatitis transmitted by exotic marine snail. Emerg Infect Dis [online] 2010 Sep, 16(9):1357-65 [viewed 21 August 2014] Available from: doi:10.3201/eid1609.091664

Investigations - for Diagnosis

Fact Explanation
Parasitologic diagnosis Extraction of the gravid flea and/ or their eggs in the lesion using a sterile needle is diagnostic and therapeutic. [1,2,3]
Dermoscopy A typical lesion with central, irregular, brown discoloration with a middle plugged opening or a gray-blue discoloration can be identified through dermoscopy. [1,2,3]
References
  1. MACO V, TANTALEáN M, GOTUZZO E. Evidence of tungiasis in pre-Hispanic America. Emerg Infect Dis [online] 2011 May, 17(5):855-62 [viewed 21 August 2014] Available from: doi:10.3201/eid1705.100542
  2. WINTER B, OLIVEIRA FA, WILCKE T, HEUKELBACH J, FELDMEIER H. Tungiasis-related knowledge and treatment practices in two endemic communities in northeast Brazil. J Infect Dev Ctries [online] 2009 Jul 1, 3(6):458-66 [viewed 21 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/19762960
  3. MAZIGO HD, BEHAMANA E, ZINGA M, HEUKELBACH J. Tungiasis infestation in Tanzania. J Infect Dev Ctries [online] 2010 Mar 29, 4(3):187-9 [viewed 21 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/20351463

Management - General Measures

Fact Explanation
Tetanus toxoid Tetanus prophylaxis is indicated for patients whose tetanus vaccination status is unknown or not up-to-date. [1,2]
Prevention The infestation can be avoided by wearing shoes when traveling in endemic areas. Insecticide such as malathion praying on the ground is also helpful. [1,2]
References
  1. JACKSON A, STEVENSON L, COGGESHALL P, WHITMAN TJ. A patient returning from Africa finds a mass imbedded in the skin of her right foot. Tungiasis. Clin Infect Dis [online] 2012 Nov, 55(9):1227, 1273-4 [viewed 21 August 2014] Available from: doi:10.1093/cid/cis607
  2. MACO V, TANTALEáN M, GOTUZZO E. Evidence of tungiasis in pre-Hispanic America. Emerg Infect Dis [online] 2011 May, 17(5):855-62 [viewed 21 August 2014] Available from: doi:10.3201/eid1705.100542

Management - Specific Treatments

Fact Explanation
Watchful waiting Most of the lesions heal themselves within 2 weeks of time. The flea dies and naturally sloughs off as the skin sheds. [1,2,3]
Physical removal of the flea A sterile needle or forceps can be used to remove the infested flea from the lesion. This is possible in small lesions where the flea is small enough to pull out through the opening. The lesion has to be cut open in case of the flea is engorged. [1,2,3,4]
Topical ivermectin Local application of anti-parasitic drugs such as ivermectin, metrifonate, and thiabendazole has been proven successful. [3,4,5]
cryotherapy Locally freezing the lesion using liquid nitrogen can be effective. [1,3,4]
Antibiotics Topical antibiotics may be instituted if secondary infection is suspected. Antibiotic treatment should be systemic if the superinfection is severe. [2,3,4]
References
  1. MACO V, TANTALEáN M, GOTUZZO E. Evidence of tungiasis in pre-Hispanic America. Emerg Infect Dis [online] 2011 May, 17(5):855-62 [viewed 21 August 2014] Available from: doi:10.3201/eid1705.100542
  2. JACKSON A, STEVENSON L, COGGESHALL P, WHITMAN TJ. A patient returning from Africa finds a mass imbedded in the skin of her right foot. Tungiasis. Clin Infect Dis [online] 2012 Nov, 55(9):1227, 1273-4 [viewed 21 August 2014] Available from: doi:10.1093/cid/cis607
  3. WINTER B, OLIVEIRA FA, WILCKE T, HEUKELBACH J, FELDMEIER H. Tungiasis-related knowledge and treatment practices in two endemic communities in northeast Brazil. J Infect Dev Ctries [online] 2009 Jul 1, 3(6):458-66 [viewed 21 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/19762960
  4. MAZIGO HD, BEHAMANA E, ZINGA M, HEUKELBACH J. Tungiasis infestation in Tanzania. J Infect Dev Ctries [online] 2010 Mar 29, 4(3):187-9 [viewed 21 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/20351463
  5. CRIADO PR, LANDMAN G, REIS VM, BELDA W JR. Tungiasis under dermoscopy: in vivo and ex vivo examination of the cutaneous infestation due to Tunga penetrans. An Bras Dermatol [online] 2013 Jul-Aug, 88(4):649-51 [viewed 21 August 2014] Available from: doi:10.1590/abd1806-4841.20132071