Lyme disease - Cellulitis
Within days to weeks, the spirochete disseminates to the nervous system, heart, joints, and other organs. At this time, patients may develop acute neurologic abnormalities, atrioventricular block, myocarditis, and disseminated skin lesions of erythema migrans (early disseminated disease). (Note: Cardiac symptoms in patients with proven or suspected Lyme disease should be carefully and expeditiously evaluated.) Months later, untreated patients may develop arthritis, an encephalopathy, a neuropathy, and, in Europe, acrodermatitis chronica atrophicans (late disease).
It is a common tick borne illness with widespread distribution but has a higher prevalence in the US and Europe. In the US, Lyme disease is primarily seen in the coastal areas of New England and south to Maryland, in the upper Midwest states of Wisconsin and Minnesota, and coastal areas of California and Oregon. It is endemic to most of Europe.
Lyme disease is subdivided clinically into 3 phases:
- Early localized disease
- Early disseminated disease
- Persisting late disease
Early localized disease, also known as erythema migrans, presents a few days to a month after a tick bite. The characteristic lesion of Lyme disease, erythema migrans, develops in some, but not all, patients. If left untreated, the disease disseminates to lymph nodes hematogenously. Outside the US, early lesions sometimes present as Borrelia lymphocytomas.
Multiple skin lesions can represent hematogenous spread (early disseminated disease) or, in rare cases, result from independent primary tick bites. Burning and itching can occur at the site of the tick bite and in erythema migrans. Initial infection is typically associated with flu-like symptoms, headache, arthralgias, and neck pain. Early neurologic symptoms can include facial nerve paralysis (Bell palsy). Atrioventricular block can persist over a few days or last a few weeks, while the arthritis of Lyme disease usually develops later, either a few months to 2 years after initial infection.
Late disease commonly presents as acrodermatitis chronica atrophicans, which is very rare in the US, with chronic blue-red patches over the extensor surfaces.
A69.20 – Lyme disease, unspecified
23502006 – Lyme disease
- Erythema annulare centrifugum has a fine collarette of scaling inside the border of the lesion (trailing scale).
- Southern tick-associated rash illness (STARI) clinically presents with erythema migrans but is transmitted by the lone star tick Amblyomma americanum.
- Arthropod bite develops rapidly after bite.
- Fixed drug reactions tend to be pigmented and do not expand.
- Tinea corporis – Associated lesions have overlying scale.
- Contact dermatitis develops vesicles or bullae within lesion.
- Erysipelas / cellulitis has a more rapid onset with homogenous erythema as it expands from the site of initial infection.
- Erythema multiforme lesions tend to have a dusky center; are symmetrically distributed favoring the dorsal hands, face, and forearms; and are usually with associated herpes infection.
- Secondary syphilis can have a characteristic "rust" color and overlying scale.
- Pityriasis rosea presents with a herald patch and lesions in characteristic "fir tree" distribution over the trunk with overlying fine scale.
- Urticarial lesions are edematous, pruritic, and typically resolve within 24 hours.
- Pseudolymphoma (lymphocytoma)
- A number of stimuli, including arthropod bites, can cause an inflammatory reaction pattern in the skin leading to the formation of nodular lesions clinically and histologically resembling cutaneous lymphoma, called pseudolymphoma. Borrelia lymphocytoma is a subset of pseudolymphomas.
- Nodular scabies are more common in the groin and extremely pruritic.
- Arthropod bite granuloma can be firm and typically does not expand.
- Malignancy (eg, breast cancer) presents with firm papules and nodules.
- Granuloma faciale
- Sarcoidosis lesions are characteristically violaceous.
- Circulatory insufficiency.
- Lupus presents with photosensitivity, malar rash, and systemic symptoms of myalgias, arthralgias, and other organ involvement.